fill

Fill all elements within a portion of an array with a specified value.

Installation

npm install @stdlib/array-base-fill

Usage

var fill = require( '@stdlib/array-base-fill' );

fill( x, value, start, end )

Fills all elements within a portion of an array from an inclusive start index to an exclusive end index with a specified value.

var x = [ 1, 2, 3, 4, 5, 6 ];

var out = fill( x, 10, 1, 4 );
// returns [ 1, 10, 10, 10, 5, 6 ]

var bool = ( out === x );
// returns true

Notes

• If provided an array-like object having a fill method, the function defers execution to that method and assumes that the method API has the following signature:

  x.fill( value, start, end )

• If provided an array-like object without a fill method, the function manually sets input array elements to a provided fill value.

• Negative start and end indices are resolved to positive indices by counting from the end of the array with -1 corresponding to the last indexed element.

• The function mutates the input array.

Examples

var Float64Array = require( '@stdlib/array-float64' );
var zeroTo = require( '@stdlib/array-base-zero-to' );
var fill = require( '@stdlib/array-base-fill' );

var x = new Float64Array( zeroTo( 6 ) );
// returns <Float64Array>[ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ]

var y = fill( x, 10.0, 0, 6 );
// returns <Float64Array>[ 10.0, 10.0, 10.0, 10.0, 10.0, 10.0 ]

y = fill( x, 0.0, 0, 4 );
// returns <Float64Array>[ 0.0, 0.0, 0.0, 0.0, 10.0, 10.0 ]

y = fill( x, 20.0, 2, 6 );
// returns <Float64Array>[ 0.0, 0.0, 20.0, 20.0, 20.0, 20.0 ]

y = fill( x, 30.0, 2, 4 );
// returns <Float64Array>[ 0.0, 0.0, 30.0, 30.0, 20.0, 20.0 ]

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.