GoScrobble/web/node_modules/core-js-pure/modules/es.string.substr.js

27 lines
976 B
JavaScript

'use strict';
var $ = require('../internals/export');
var requireObjectCoercible = require('../internals/require-object-coercible');
var toInteger = require('../internals/to-integer');
var toString = require('../internals/to-string');
var slice = ''.slice;
var max = Math.max;
var min = Math.min;
// `String.prototype.substr` method
// https://tc39.es/ecma262/#sec-string.prototype.substr
$({ target: 'String', proto: true }, {
substr: function substr(start, length) {
var that = toString(requireObjectCoercible(this));
var size = that.length;
var intStart = toInteger(start);
var intLength, intEnd;
if (intStart === Infinity) intStart = 0;
if (intStart < 0) intStart = max(size + intStart, 0);
intLength = length === undefined ? size : toInteger(length);
if (intLength <= 0 || intLength === Infinity) return '';
intEnd = min(intStart + intLength, size);
return intStart >= intEnd ? '' : slice.call(that, intStart, intEnd);
}
});