replaceBefore

Replace the substring before the first occurrence of a specified search string.

Usage

var replaceBefore = require( '@stdlib/string/base/replace-before' );

replaceBefore( str, search, replacement, fromIndex )

Replaces the substring before the first occurrence of a specified search string.

var out = replaceBefore( 'beep boop', ' ', 'loop', 0 );
// returns 'loop boop'

out = replaceBefore( 'beep boop', 'o', 'bar', 0 );
// returns 'baroop'

To begin searching from a specific index, provide a corresponding fromIndex argument.

var out = replaceBefore( 'beep boop', 'p', 'bar', 5 );
// returns 'barp'

If fromIndex is less than zero, the starting index is resolved relative to the last string character, with the last string character corresponding to fromIndex = -1.

var out = replaceBefore( 'beep boop beep', ' ', 'loop', -6 );
// returns 'loop beep'

Notes

If a search string is not present in a provided string, the function returns the provided string unchanged.
If a search string is an empty string, the function returns the provided string unchanged.
If fromIndex resolves to an index which is greater than or equal to str.length, the function returns the provided string unchanged.

Examples

var replaceBefore = require( '@stdlib/string/base/replace-before' );

var out = replaceBefore( 'beep boop', 'p', 'see', 0 );
// returns 'seep boop'

out = replaceBefore( 'Hello World!', 'xyz', 'foo', 0 );
// returns 'Hello World!'

out = replaceBefore( 'Hello World!', '', 'foo', 0 );
// returns 'Hello World!'

out = replaceBefore( '', 'xyz', 'foo', 0 );
// returns ''