Benchmark: String indexing vs array indexing for string concatenation

String indexing vs array indexing for string concatenation (version: 2)

Performance of different methods of buffer/array indexing to use characters in joined string.

Comparing performance of: Array Indexing + concatenate string vs String Indexing: with array index + concatenate string vs Create loop Char Array + Array Indexing concatenation vs Split create char Array + Array Indexing concatenation vs String Indexing: with .charAt() + concatenate string vs String Indexing: with .at() + concatenate string vs String Indexing: with .slice() + concatenate string vs Array Indexing: with array index + concatenate string foreach vs Array Indexing: with array index + concatenate string while decrement

Created: one year ago by: Registered User

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HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

const string = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque eget venenatis eros."
const array = string.split('');

Tests:

Array Indexing + concatenate string
let output = '' for(let i = 0; i < array.length; i++){ output += array[ i ]; }
String Indexing: with array index + concatenate string
let output = '' for(let i = 0; i < string.length; i++){ output += string[ i ]; }
Create loop Char Array + Array Indexing concatenation
const charArray = []; for(let i = 0; i < string.length; i++){ charArray.push(string[ i ]); } let output = '' for(let i = 0; i < charArray.length; i++){ output += charArray[ i ]; }
Split create char Array + Array Indexing concatenation
const charArray = string.split(''); let output = '' for(let i = 0; i < charArray.length; i++){ output += charArray[ i ]; }
String Indexing: with .charAt() + concatenate string
let output = '' for(let i = 0; i < string.length; i++){ output += string.charAt(i); }
String Indexing: with .at() + concatenate string
let output = '' for(let i = 0; i < string.length; i++){ output += string.at(i); }
String Indexing: with .slice() + concatenate string
let output = '' for(let i = 1; i <= string.length; i++){ output += string.slice(i - 1, i); }
Array Indexing: with array index + concatenate string foreach
let output = '' for(const char of array){ output += array[i] }
Array Indexing: with array index + concatenate string while decrement
let output = '' let index = array.length; while (--index){ output += array[array.length - 1 - i] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array Indexing + concatenate string
String Indexing: with array index + concatenate string
Create loop Char Array + Array Indexing concatenation
Split create char Array + Array Indexing concatenation
String Indexing: with .charAt() + concatenate string
String Indexing: with .at() + concatenate string
String Indexing: with .slice() + concatenate string
Array Indexing: with array index + concatenate string foreach
Array Indexing: with array index + concatenate string while decrement

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36 Edg/118.0.2088.46

Browser/OS: Chrome 118 on Linux

View result in a separate tab

Split create char Array + Array Indexing concatenation

2.1M/s

Array Indexing + concatenate string

1.8M/s

String Indexing: with .charAt() + concatenate string

1.7M/s

String Indexing: with array index + concatenate string

1.7M/s

Array Indexing: with array index + concatenate string foreach

1.6M/s

Array Indexing: with array index + concatenate string while decrement

1.5M/s

String Indexing: with .slice() + concatenate string

1.3M/s

String Indexing: with .at() + concatenate string

1.1M/s

Create loop Char Array + Array Indexing concatenation

649K/s

View exact numbers

Test name	Executions per second
✓ Split create char Array + Array Indexing concatenation	2,070,137 Ops/sec
Array Indexing + concatenate string	1,773,318 Ops/sec
String Indexing: with .charAt() + concatenate string	1,674,440 Ops/sec
String Indexing: with array index + concatenate string	1,657,360 Ops/sec
Array Indexing: with array index + concatenate string foreach	1,568,695 Ops/sec
Array Indexing: with array index + concatenate string while decrement	1,502,375 Ops/sec
String Indexing: with .slice() + concatenate string	1,308,943 Ops/sec
String Indexing: with .at() + concatenate string	1,076,967 Ops/sec
Create loop Char Array + Array Indexing concatenation	648,656 Ops/sec