es6.array.slice.js 909 B

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  1. 'use strict';
  2. var $export = require('./_export')
  3. , html = require('./_html')
  4. , cof = require('./_cof')
  5. , toIndex = require('./_to-index')
  6. , toLength = require('./_to-length')
  7. , arraySlice = [].slice;
  8. // fallback for not array-like ES3 strings and DOM objects
  9. $export($export.P + $export.F * require('./_fails')(function(){
  10. if(html)arraySlice.call(html);
  11. }), 'Array', {
  12. slice: function slice(begin, end){
  13. var len = toLength(this.length)
  14. , klass = cof(this);
  15. end = end === undefined ? len : end;
  16. if(klass == 'Array')return arraySlice.call(this, begin, end);
  17. var start = toIndex(begin, len)
  18. , upTo = toIndex(end, len)
  19. , size = toLength(upTo - start)
  20. , cloned = Array(size)
  21. , i = 0;
  22. for(; i < size; i++)cloned[i] = klass == 'String'
  23. ? this.charAt(start + i)
  24. : this[start + i];
  25. return cloned;
  26. }
  27. });