​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript Array.map()</h1>
​
<p>通过对每个数组元素执行函数来创建新数组。</p>
​
<p id="demo"></p>
​
<script>
var numbers1 = [45, 4, 9, 16, 25];
var numbers2 = numbers1.map(myFunction);
​
document.getElementById("demo").innerHTML = numbers2;
​
function myFunction(value, index, array) {
  return value * 2;
}
</script>
​
</body>
</html>
​