JS String Prototype Slice - thelastmile/FreeCodeCamp GitHub Wiki

JavaScript String.prototype.slice()

The JavaScript string method .slice() extracts a portion of a string and returns a new string.

Syntax

str.slice(beginSliceIndex[, endSliceIndex]);

Parameters

beginSliceIndex

The zero-based index where the slice should begin. If beginSliceIndex is a negative number, .slice() counts backwards from the end of the string to determine where to begin the slice.

endSliceIndex

Optional. The zero-based index where the slice should end. If omitted, .slice() extracts to the end of the string.

Description

.slice() slices the text out of one string and returns a new string.

Examples

Using .slice() to create a new string

var string1 = "Hello World!";
var string2 = string1.slice(3);
console.log(string2);                           // Will log "lo World!"

var string3 = string1.slice(3, 7);
console.log(string3);                           // Will log "lo W"

Using .slice() with negative indices

var string = "Hello World!"
str.slice(-3);                                  // Returns "ld!"
str.slice(-3, -1);                              // Returns "ld"
str.slice(0, -1);                               // Returns "Hello World"

Source MDN