Array.prototype.entries() - JavaScript 编辑

The entries() method returns a new Array Iterator object that contains the key/value pairs for each index in the array.

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Syntax

array.entries()

Return value

A new Array iterator object.

Examples

Iterating with index and element

const a = ['a', 'b', 'c'];

for (const [index, element] of a.entries())
  console.log(index, element);

// 0 'a'
// 1 'b'
// 2 'c'

Using a for…of loop

var a = ['a', 'b', 'c'];
var iterator = a.entries();

for (let e of iterator) {
  console.log(e);
}
// [0, 'a']
// [1, 'b']
// [2, 'c']

Specifications

Browser compatibility

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See also

• Array.prototype.keys()
• Array.prototype.values()
• Array.prototype.forEach()
• Array.prototype.every()
• Array.prototype.some()
• for...of
• Iteration protocols