JavaScript 函数 Apply

方法重用

通过 apply() 方法，您能够编写用于不同对象的方法。

JavaScript apply() 方法

apply() 方法与 call() 方法非常相似：

在本例中，person 的 fullName 方法被应用到 person1：

Ƙasashin

var person = {
    fullName: function() {
        return this.firstName + " " + this.lastName;
    }
}
var person1 = {
    firstName: "Bill",
    lastName: "Gates",
}
person.fullName.apply(person1);  // 将返回 "Bill Gates"

Ƙarƙin ƙa'idar

call() 和 apply() 之间的区别

不同之处是：

call() 方法分别接受参数。

apply() 方法接受数组形式的参数。

如果要使用数组而不是参数列表，则 apply() 方法非常方便。

带参数的 apply() 方法

apply() 方法接受数组中的参数：

Ƙasashin

var person = {
  fullName: function(city, country) {
    return this.firstName + " " + this.lastName + "," + city + "," + country;
  }
}
var person1 = {
  firstName:\"Bill\",
  lastName: "Gates"
}
person.fullName.apply(person1, ["Oslo", "Norway"]);

Ƙarƙin ƙa'idar

与 call() 方法对比：

Ƙasashin

var person = {
  fullName: function(city, country) {
    return this.firstName + " " + this.lastName + "," + city + "," + country;
  }
}
var person1 = {
  firstName:\"Bill\",
  lastName: "Gates"
}
person.fullName.call(person1, "Oslo", "Norway");

Ƙarƙin ƙa'idar

ƙarƙin max ƙwararru kan ƙanƙa

A iya amfani da Math.max() ƙwamfara na ƙarƙin ƙwararru na ƙarƙin (ƙa'idar ƙwararru na ƙarƙin):

Ƙasashin

Math.max(1,2,3);  // ƙarƙin zai cika 3

Ƙarƙin ƙa'idar

Kama ƙanƙa JavaScript ba ƙa'idar max() ba, kuma iya amfani da Math.max() Ƙwamfara.

Ƙasashin

Math.max.apply(null, [1,2,3]); // ƙarƙin zai cika 3

Ƙarƙin ƙa'idar

Ƙwararru na farko (null) ba za a ƙara da ita ba. A wannan ƙarƙin, a ƙarƙi a ƙarƙi ba a ƙarƙi ba.

Ƙasashin na wa ƙarƙin yana cika cikin wannan ƙarƙin:

Ƙasashin

Math.max.apply(Math, [1,2,3]); // ƙarƙin zai cika 3

Ƙarƙin ƙa'idar

Ƙasashin

Math.max.apply(" ", [1,2,3]); // ƙarƙin zai cika 3

Ƙarƙin ƙa'idar

Ƙasashin

Math.max.apply(0, [1,2,3]); // ƙarƙin zai cika 3

Ƙarƙin ƙa'idar

ƙa'idar ƙarƙin JavaScript

A ƙarƙin ƙa'idar JavaScript, idan apply() Ƙwararru na farko ba ƙan ƙoƙarin, kuma ya zama ƙarƙin ƙwamfara da a ƙara. A ƙarƙin ƙa'idar 'ƙarƙin ƙa'idar', ya zama ƙarƙin ƙwararru.