array.prototype.entries's Introduction

array.prototype.entries

An ES2015 spec-compliant Array.prototype.entries shim/polyfill/replacement that works as far down as ES3.

This package implements the es-shim API interface. It works in an ES3-supported environment and complies with the spec.

Because Array.prototype.entries depends on a receiver (the “this” value), the main export takes the array to operate on as the first argument.

Example

var entries = require('array.prototype.entries');
var assert = require('assert');
var iterate = require('iterate-iterator');

assert.deepStrictEqual(iterate(entries([1, 2, 3])), [[0, 1], [1, 2], [2, 3]]);
assert.deepStrictEqual(iterate(entries([1, 0, 1])), [[0, 1], [1, 0], [2, 1]]);
assert.deepStrictEqual(iterate(entries([NaN])), [[0, NaN]]);
assert.deepStrictEqual(iterate(entries([1,,3])), [[0, 1], [1, undefined], [2, 3]]);

var entries = require('array.prototype.entries');
var assert = require('assert');
/* when Array#entries is not present */
delete Array.prototype.entries;
var shimmedMap = entries.shim();
assert.deepStrictEqual(shimmedMap, entries.getPolyfill());
assert.deepStrictEqual(iterate([1, 2, 3].entries()), [[0, 1], [1, 2], [2, 3]]);
assert.deepStrictEqual(iterate([1, 0, 1].entries()), [[0, 1], [1, 0], [2, 1]]);
assert.deepStrictEqual(iterate([NaN].entries()), [[0, NaN]]);
assert.deepStrictEqual(iterate([1,,3].entries()), [[0, 1], [1, undefined], [2, 3]]);

var entries = require('array.prototype.entries');
var assert = require('assert');
/* when Array#entries is present */
var shimmedMap = entries.shim();
assert.equal(shimmedMap, Array.prototype.entries);
assert.deepStrictEqual(iterate([1, 2, 3].entries()), [[0, 1], [1, 2], [2, 3]]);