time-to-botec

Benchmark sampling in different programming languages
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ends_with.js (2993B)

      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 isInteger = require( '@stdlib/assert/is-integer' ).isPrimitive;
     24 var isString = require( '@stdlib/assert/is-string' ).isPrimitive;
     25 var format = require( './../../format' );
     26 
     27 
     28 // MAIN //
     29 
     30 /**
     31 * Test if a string ends with the characters of another string.
     32 *
     33 * @param {string} str - input string
     34 * @param {string} search - search string
     35 * @param {integer} [len=str.length] - substring length
     36 * @throws {TypeError} first argument must be a string
     37 * @throws {TypeError} second argument must be a string
     38 * @throws {TypeError} third argument must be an integer
     39 * @returns {boolean} boolean indicating if the input string ends with the search string
     40 *
     41 * @example
     42 * var bool = endsWith( 'Remember the story I used to tell you when you were a boy?', 'boy?' );
     43 * // returns true
     44 *
     45 * @example
     46 * var bool = endsWith( 'Remember the story I used to tell you when you were a boy?', 'Boy?' );
     47 * // returns false
     48 *
     49 * @example
     50 * var bool = endsWith( 'To be, or not to be, that is the question.', 'to be' );
     51 * // returns false
     52 *
     53 * @example
     54 * var bool = endsWith( 'To be, or not to be, that is the question.', 'to be', 19 );
     55 * // returns true
     56 *
     57 * @example
     58 * var bool = endsWith( 'To be, or not to be, that is the question.', 'to be', -23 );
     59 * // returns true
     60 */
     61 function endsWith( str, search, len ) {
     62 	var idx;
     63 	var i;
     64 	if ( !isString( str ) ) {
     65 		throw new TypeError( format( 'invalid argument. First argument must be a string. Value: `%s`.', str ) );
     66 	}
     67 	if ( !isString( search ) ) {
     68 		throw new TypeError( format( 'invalid argument. Second argument must be a string. Value: `%s`.', search ) );
     69 	}
     70 	if ( arguments.length > 2 ) {
     71 		if ( !isInteger( len ) ) {
     72 			throw new TypeError( format( 'invalid argument. Third argument must be an integer. Value: `%s`.', len ) );
     73 		}
     74 		if ( len === 0 ) {
     75 			return ( search.length === 0 );
     76 		}
     77 		if ( len < 0 ) {
     78 			idx = str.length + len;
     79 		} else {
     80 			idx = len;
     81 		}
     82 	} else {
     83 		idx = str.length;
     84 	}
     85 	if ( search.length === 0 ) {
     86 		// Based on the premise that every string can be "surrounded" by empty strings (e.g., "" + "a" + "" + "b" + "" === "ab"):
     87 		return true;
     88 	}
     89 	idx -= search.length;
     90 	if ( idx < 0 ) {
     91 		return false;
     92 	}
     93 	for ( i = 0; i < search.length; i++) {
     94 		if ( str.charCodeAt( idx + i ) !== search.charCodeAt( i ) ) {
     95 			return false;
     96 		}
     97 	}
     98 	return true;
     99 }
    100 
    101 
    102 // EXPORTS //
    103 
    104 module.exports = endsWith;