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normalizeSlice

Normalize a Slice object.

Installation

npm install @stdlib/slice-base-normalize-slice

Alternatively,

To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
If you are using Deno, visit the deno branch (see README for usage intructions).
For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var normalizeSlice = require( '@stdlib/slice-base-normalize-slice' );

normalizeSlice( slice, len, strict )

Normalizes a Slice object, where len specifies the maximum number of elements allowed in the slice.

var Slice = require( '@stdlib/slice-ctor' );

var s = normalizeSlice( new Slice( -1, null, -1 ), 10, false );
// returns <Slice>

var v = s.start;
// returns 9

v = s.stop;
// returns null

v = s.step;
// returns -1

When strict is true, the function returns an error object if an input slice exceeds index bounds.

var Slice = require( '@stdlib/slice-ctor' );

var s = normalizeSlice( new Slice( -20, 20, 1 ), 10, true );
// returns { 'code': 'ERR_SLICE_OUT_OF_BOUNDS' }

A returned error object may have one of the following error codes:

ERR_SLICE_OUT_OF_BOUNDS: a slice exceeds index bounds.

Examples

var Slice = require( '@stdlib/slice-ctor' );
var normalizeSlice = require( '@stdlib/slice-base-normalize-slice' );

var s = normalizeSlice( new Slice(), 5, false );
console.log( 'start: %s. stop: %s. step: %s.', s.start, s.stop, s.step );
// => 'start: 0. stop: 5. step: 1.'

s = normalizeSlice( new Slice( 1, 4, 2 ), 5, false );
console.log( 'start: %s. stop: %s. step: %s.', s.start, s.stop, s.step );
// => 'start: 1. stop: 4. step: 2.'

s = normalizeSlice( new Slice( -1, null, -1 ), 5, false );
console.log( 'start: %s. stop: %s. step: %s.', s.start, s.stop, s.step );
// => 'start: 4. stop: null. step: -1.'

s = normalizeSlice( new Slice( -10, -2, 2 ), 5, false );
console.log( 'start: %s. stop: %s. step: %s.', s.start, s.stop, s.step );
// => 'start: 0. stop: 3. step: 2.'

s = normalizeSlice( new Slice( 1, 20, 2 ), 5, false );
console.log( 'start: %s. stop: %s. step: %s.', s.start, s.stop, s.step );
// => 'start: 1. stop: 5. step: 2.'

See Also

@stdlib/slice-base/normalize-multi-slice: normalize a MultiSlice object.

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.

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