pop.js (2285B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var isArray = require( '@stdlib/assert/is-array' ); 24 var isTypedArrayLike = require( '@stdlib/assert/is-typed-array-like' ); 25 var isInteger = require( '@stdlib/assert/is-integer' ); 26 var popObject = require( './pop_object.js' ); 27 var popTypedArray = require( './pop_typed_array.js' ); 28 29 30 // MAIN // 31 32 /** 33 * Removes and returns the last element of a collection. 34 * 35 * @param {(Array|TypedArray|Object)} collection - collection 36 * @throws {TypeError} must provide either an array, typed array, or an array-like object 37 * @returns {Array} updated collection and the removed element 38 * 39 * @example 40 * var arr = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; 41 * 42 * var out = pop( arr ); 43 * // returns [ [ 1.0, 2.0, 3.0, 4.0 ], 5.0 ] 44 * 45 * @example 46 * var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0 ] ); 47 * // returns <Float64Array>[ 1.0, 2.0, 3.0, 4.0, 5.0 ] 48 * 49 * var out = pop( arr ); 50 * // returns [ <Float64Array>[ 1.0, 2.0, 3.0, 4.0 ], 5.0 ] 51 */ 52 function pop( collection ) { 53 var v; 54 if ( isArray( collection ) ) { 55 v = collection.pop(); 56 return [ collection, v ]; 57 } 58 // Check for a typed-array-like object, as verifying actual typed arrays is expensive... 59 if ( isTypedArrayLike( collection ) ) { 60 return popTypedArray( collection ); 61 } 62 // Check for an array-like object... 63 if ( 64 collection !== null && 65 typeof collection === 'object' && 66 typeof collection.length === 'number' && 67 isInteger( collection.length ) && 68 collection.length >= 0 69 ) { 70 return popObject( collection ); 71 } 72 throw new TypeError( 'invalid argument. Must provide either an Array, Typed Array, or an array-like Object. Value: `'+collection+'`.' ); 73 } 74 75 76 // EXPORTS // 77 78 module.exports = pop;