time-to-botec

Benchmark sampling in different programming languages
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_isIndex.js (759B)

      1 /** Used as references for various `Number` constants. */
      2 var MAX_SAFE_INTEGER = 9007199254740991;
      3 
      4 /** Used to detect unsigned integer values. */
      5 var reIsUint = /^(?:0|[1-9]\d*)$/;
      6 
      7 /**
      8  * Checks if `value` is a valid array-like index.
      9  *
     10  * @private
     11  * @param {*} value The value to check.
     12  * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
     13  * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
     14  */
     15 function isIndex(value, length) {
     16   var type = typeof value;
     17   length = length == null ? MAX_SAFE_INTEGER : length;
     18 
     19   return !!length &&
     20     (type == 'number' ||
     21       (type != 'symbol' && reIsUint.test(value))) &&
     22         (value > -1 && value % 1 == 0 && value < length);
     23 }
     24 
     25 module.exports = isIndex;