JavaScript之遍历数组

for遍历

var arr = [1, 2, 3, 4];
for (var i = 0; i < arr.length; i++) {
    console.log(arr[i]);
}

forEach遍历

var arr = [1, 2, 3, 4];
arr.forEach(function(val, index) {
    console.log(val, index);
});

for-in遍历

var arr = [1, 2, 3, 4];
for (var i in arr) {
    console.log(arr[i]);
}

$.each遍历（要引入jQuery）

var arr = [1, 2, 3, 4];
   $.each(arr, function (index, val) {
   document.write("索入"+index+":"+val+'\n');
});