Javascript i wydajność - czy to się spina?

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Transcript of Javascript i wydajność - czy to się spina?

JAVASCRIPT I WYDAJNOŚĆ TO SIĘ SPINA?

AGENDA 01 Wprowadzenie 02 Restrykcje są cool 03 Po co się powtarzać? 04 Jeśli, a co jeśli nie? 05 Za dużo gadam 06 Przesuń to, przesuń tamto 07 TL;DR

01WPROWADZENIE

GLOBAL DIGITAL AGENCY1,900+ EMPLOYEES

ATLANTABEIJINGBOGOTÁBOSTONCAPE TOWNCHICAGO

GUANGZHOUJAKARTAJOHANNESBURGKALAMAZOOKANSAS CITYKRAKOW

LONDONMILANMUMBAINEW YORKSÃO PAULOSEATTLE

SHANGHAISINGAPORESYDNEYTOKYOWARSAWWHITE SALMON

PO CO TA PREZENTACJA

PRZYKŁADOWY KOD - ODWROTNA NOTACJA POLSKAfor (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

PRZYKŁADOWY KOD - ODWROTNA NOTACJA POLSKAfor (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

(2+3)*5

2 3 + 5 *

w odwrotnej notacji polskiej

PRZYKŁADOWY KOD - ODWROTNA NOTACJA POLSKAfor (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

(2+3)*5

2 3 + 5 *

w odwrotnej notacji polskiej

75 ms

~13fps

CO MOŻNA Z TYM ZROBIĆ?

02RESTRYKCJE SĄ COOL

ODWROTNA NOTACJA POLSKAfor (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

for (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

STRICT MODE

’use strict’;

for (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

STRICT MODE’use strict’;

03PO CO SIĘ POWTARZAĆ

’use strict’; for (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

ODWROTNA NOTACJA POLSKA

’use strict’; for (let i = 0; i < 10000; i++) { let stack = []; let str = '12 2 3 4 * 10 5 / + * +'; str = str.split(" "); let output = []; let currentOp = []; let num = 0; let string; for (let i in str) { num = parseInt(str[i]); if (isNaN(num)) { string = num.toString(); stack.push(str[i]); if (str.length > 0) { if (isNaN(str[i])) { output.push(stack.pop()); currentOp = []; for (let i = 0; i < 3; i++) { currentOp.push(output.pop()); this.popped = currentOp.reverse(); let x = currentOp[0]; let y = currentOp[2]; this.result = 0; if (currentOp[1] === "*") { result = x * y } else if (currentOp[1] === "/") { result = x / y } else if (currentOp[1] === "-") { result = x - y } else if (currentOp[1] === "+") { result = x + y } else if (currentOp[1] === "^") { result = Math.pow(x, y) } } output.push(result); } } } else { output.push(num); } } }

ODWROTNA NOTACJA POLSKA

REFACTORING ❤

’use strict’; for (let i = 0; i < 10000; i++) { let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

DELEGACJA ZADAŃ DO DEDYKOWANYCH FUNKCJI

’use strict’; for (let i = 0; i < 10000; i++) { let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

DELEGACJA ZADAŃ DO DEDYKOWANYCH FUNKCJI

DELEGACJA ZADAŃ DO DEDYKOWANYCH FUNKCJI - PORÓWNANIE

13.72 ops/s 41.59 ops/s

04JEŚLI, A CO JEŚLI NIE?

WYŻSZOŚĆ IF/ELSE

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

WYŻSZOŚĆ IF/ELSE

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

var x = true;var y = false;switch(true) {

case (x || y)://…

}

WYŻSZOŚĆ IF/ELSE

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

var x = true;var y = false;switch(true) {

case (x || y)://…

}

WYŻSZOŚĆ IF/ELSE

let performOperation = (symbol, val2, val1) => { switch(symbol) { case '*': return val1 * val2; case '/': return val1 / val2; case '+': return +val1 + +val2; case '-': return +val1 - +val2; case '^': return Math.pow(val1, val2); } }

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

WYŻSZOŚĆ IF/ELSE

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

WYŻSZOŚĆ IF/ELSE

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num); if (isOperatorSymbol) { let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num, value1, value2)); } else { numArray.push(num); } } }

let performOperation = (symbol, val2, val1) => {if (symbol == '*') { return val1*val2; }else if (symbol == '/') { return val1/val2; }else if (symbol == '+') { return +val1 + +val2; }else if (symbol == '-') { return +val1 - +val2; }else if (symbol == '^') { return Math.pow(val1, val2); }

}

05ZA DUŻO GADAM

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) { let num = toBeInterpeted[i]; let isOperatorSymbol = isOperator(num);

if (isOperatorSymbol) {

let performOperation = (symbol,

let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num,

numArray.push(

val2, val1) => {

value1, value2));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

if (isOperatorSymbol) {

let performOperation = (symbol,

let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num,

numArray.push(

val2, val1) => {

value1, value2));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val2, val1) => {

value1, value2));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

let value2 = numArray.pop(); let value1 = numArray.pop(); numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

value1, value2));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

value1, value2));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

numArray.pop(), numArray.pop()));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

numArray.pop(), numArray.pop()));

num);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

numArray.pop(), numArray.pop()));

toBeInterpreted[i]);

OGRANICZAMY ILOŚĆ ZMIENNYCH

let isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

let numArray = []; let input = '2 7 + 3 / 14 3 - 4 * + 2 /'; let toBeInterpeted = input.split(' ');

’use strict’; for (let i = 0; i < 10000; i++) {

} else {

} } }

if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

for(let i = 0; i < toBeInterpeted.length; i++) {

let performOperation = (symbol,

numArray.push(performOperation(num,

numArray.push(

if (isOperator(toBeInterpreted[i])) {

val1, val2) => {

numArray.pop(), numArray.pop()));

toBeInterpreted[i]);

OGRANICZAMY ILOŚĆ ZMIENNYCH - PORÓWNANIE

41.11 ops/s 200 ops/s

06PRZESUŃ TO, PRZESUŃ TAMTO

WYRZUCAMY STAŁE Z PĘTLI OBLICZENIOWEJ

isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

input = '2 7 + 3 / 14 3 - 4 * + 2 /'; toBeInterpeted = input.split(' ');

for (let i = 0; i < 10000; i++) { let numArray = [];

for(let i = 0; i < toBeInterpeted.length; i++) { if (isOperator(toBeInterpreted[i])) { numArray.push(performOperation(num, numArray.pop(), numArray.pop())); } else { numArray.push(toBeInterpreted[i]); } } }

performOperation = (symbol, val1, val2) => { if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

let let

let

let

’use strict’;

WYRZUCAMY STAŁE Z PĘTLI OBLICZENIOWEJ

isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

input = '2 7 + 3 / 14 3 - 4 * + 2 /'; toBeInterpeted = input.split(' ');

for (let i = 0; i < 10000; i++) { let numArray = []; for(let i = 0; i < toBeInterpeted.length; i++) { if (isOperator(toBeInterpreted[i])) { numArray.push(performOperation(num, numArray.pop(), numArray.pop())); } else { numArray.push(toBeInterpreted[i]); } } }

performOperation = (symbol, val1, val2) => { if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

letlet

let

let

’use strict’;

WYRZUCAMY STAŁE Z PĘTLI OBLICZENIOWEJ

isOperator = (val) => { if (val == '*' || val == '/' || val == '^' || val == '+' || val == '-') { return true; } return false; }

input = '2 7 + 3 / 14 3 - 4 * + 2 /'; toBeInterpeted = input.split(' ');

for (let i = 0; i < 10000; i++) { let numArray = []; for(let i = 0; i < toBeInterpeted.length; i++) { if (isOperator(toBeInterpreted[i])) { numArray.push(performOperation(num, numArray.pop(), numArray.pop())); } else { numArray.push(toBeInterpreted[i]); } } }

performOperation = (symbol, val1, val2) => { if (symbol == '*') { return val1*val2; } else if (symbol == '/') { return val1/val2; } else if (symbol == '+') { return +val1 + +val2; } else if (symbol == '-') { return +val1 - +val2; } else if (symbol == '^') { return Math.pow(val1, val2); } }

constconst

const

const

’use strict’;

WYRZUCAMY STAŁE Z PĘTLI OBLICZENIOWEJ - PORÓWNANIE

204 ops/s 279 ops/s

~75 ms

PODSUMOWANIE - ILE TERAZ TRWA CAŁA OPERACJA?

PODSUMOWANIE - ILE TERAZ TRWA CAŁA OPERACJA?

~3.5 ms(przyspieszenie o ~2050%)

'USE STRICT';

•kompilator nie musi się „domyślać”

•mniejsza szansa na głupi błąd

•niewielki skok wydajności

DELEGACJA ZADAŃ DO DEDYKOWANYCH FUNKCJI

•czystszy kod

•znaczny skok wydajności

IF/ELSE

•mikrooptymalizacja - do poświęcenia w celu zwiększenia czytelności kodu

•niewielki skok wydajności

OGRANICZ LICZBĘ ZMIENNYCH

•potrafi zmniejszyć czytelność kodu

•bardzo duży skok wydajności

PRZENIEŚ STAŁE Z PĘTLI OBLICZENIOWEJ

•zwiększa „reużywalność” kodu

•duży skok wydajności

TL;DR

LINKI

•https://mythbusters.js.org/

DZIĘKUJĘMichał Kostrzyński Frontend Developer michal.kostrzynski@vml.com linkedin.com/in/michalkostrzynski

Zawartość niniejszej prezentacji, a w szczególności koncepcje i sposób prezentacji treści, stanowią własność intelektualną VML Poland, chronioną prawem zgodnie z ustawą z dnia 4 lutego 1994 r. o ochronie praw autorskich i praw pokrewnych. Wykorzystanie całości lub części niniejszego utworu w jakichkolwiek celach wymaga pisemnej zgody właściciela. Niniejsza oferta zachowuje ważność przez okres 3 miesięcy od daty otrzymania.

http://frontowo.pl

https://joind.in/event/codetecon/

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