JavaScript数组遍历方法详解：some、every、filter、map与forEach

核心遍历方法详解

<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
var a = [1,2,3,4,5,6];
var b = a.some(function(ele,index,arr){
  console.log(ele);//输出1,2,3遍历到3停止遍历
  return ele > 2;
});
console.log(b);
console.log("--------------------");
var c = a.every(function(ele,index,arr){
  console.log(ele);//输出1,2,3,4,5遍历到5返回false，停止遍历
  return ele < 5;
});
console.log(c);
console.log("--------------------");
var d = a.filter(function(ele,index,arr){
  console.log(ele);//遍历整个数组，将值大于3的项添加到d数组中
  return ele > 3;
});
console.log(d);
console.log("--------------------");
var e = a.map(function(ele,index,arr){
  console.log(ele);//遍历整个数组，对数组的每个元素执行一次操作，将新的元素添加到e数组中
  return ele+3;
});
console.log(e);
console.log("--------------------");
a.forEach(function(ele,index,arr){
  arr[index] = ele+6;//遍历数组，对数组中的每项执行一次操作，无返回值
});
console.log(a);
</script>
</body>
</html>