find() 與filter() 很像，但find() 只會回傳一次值，且是第一次為true 的值。 var findEmpty = people.find(function(item, index, array){ }); ... ... <看更多>

The iterator provided by arrays provides the values of the array elements, in order beginning to end. Notice how element is scoped to each loop iteration; ... ... <看更多>

Introduction to JavaScript Array forEach() method ... Typically, when you want to execute a function on every element of an array, you use a for loop statement. ... <看更多>

Copied from https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/forEach. *. * forEach is a recent addition to the ECMA-262 standard ... ... <看更多>

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This might be a case of pre-optimization. Each call to filter will loop over the array, so your first example iterates twice. ... <看更多>