Function createSizePropertyCheck

underscore.js:214–219

(getSizeProperty)

  // Common internal logic for `isArrayLike` and `isBufferLike`.
  function createSizePropertyCheck(getSizeProperty) {
    return function(collection) {
      var sizeProperty = getSizeProperty(collection);
      return typeof sizeProperty == 'number' && sizeProperty >= 0 && sizeProperty <= MAX_ARRAY_INDEX;
    }
  }

  // Internal helper to generate a function to obtain property `key` from `obj`.
  function shallowProperty(key) {