toString()
方法的语法为:
obj.toString()
在这里, obj
是一个对象。
toString()参数
toString()
方法没有任何参数。
从toString()返回值
- 返回表示对象的字符串 。
注意 :每个从Object
派生的Object
继承toString()
,如果未重写,则返回"[object
。
示例:使用toString()
// built-in objects
let num = 10;
// number takes in optional radix argument (numeral base)
console.log(num.toString(2)); // "1010" in binary
console.log(new Date().toString()); // Thu Aug 06 2020 12:08:44 GMT+0545 (Nepal Time)
// overriding default toString(), custom object
function Dog(name, breed, sex) {
this.name = name;
this.breed = breed;
this.sex = sex;
}
dog1 = new Dog("Daniel", "bulldog", "male");
console.log(dog1.toString()); // [object Object]
Dog.prototype.toString = function dogToString() {
return `${this.name} is a ${this.sex} ${this.breed}.`;
};
console.log(dog1.toString()); // Daniel is a male bulldog.
输出
1010
Thu Aug 06 2020 12:08:44 GMT+0545 (Nepal Time)
[object Object]
Daniel is a male bulldog.
推荐读物: JavaScript Object valueOf()