前端常用的一些方法



1、js判读是否为数组

var arr1 = [];

Object.prototype.toString.call(arr1) === '[object Array]'

2、Javascript For/In 循环： 循环遍历对象的属性

var person={fname:"John",lname:"Doe",age:25};

for (x in person)
  {
    txt=txt + person[x];
  }
结果：JohnDoe25

3、jQuery jQuery.each() 遍历对象属性

var arr = ["one", "two", "three", "four", "five"];
var obj = { one: 1, two: 2, three: 3, four: 4, five: 5 };

4、遍历数组

var text = "Array ";
jQuery.each(arr, function(i, val) {
 text = text + " #Index:" + i + ":" + val;
});
console.log(text);
//Array  #Index:0:one #Index:1:two #Index:2:three #Index:3:four #Index:4:five

5、遍历对象

text = "Object ";
jQuery.each(obj, function(i, val) {
 text = text + "Key:" + i + ", Value:" + val;
});
console.log(text);
//Object Key:one, Value:1Key:two, Value:2Key:three, Value:3Key:four, Value:4Key:five, Value:5