JavaScript Object toString()用法及代碼示例

用法:

obj.toString()

在這裏，obj 是一個對象。

參數：

toString() 方法不接受任何參數。

返回：

• 返回表示對象的字符串。

注意: 每個對象都來自Object繼承toString()如果沒有被覆蓋，它會返回"[object <type>]".

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.

輸出

1010
Thu Aug 06 2020 12:08:44 GMT+0545 (Nepal Time)
[object Object]
Daniel is a male bulldog.