JavaScript Function.prototype.bind的用法是什么

Bind方法： 使用这个方法，我们可以将一个对象绑定到一个通用函数上，这样在需要时就会得到不同的结果。bind()方法接受一个对象作为参数并创建一个新函数。所以基本上bind函数返回函数。

让我们了解一下bind方法是何时使用的。

bind the object with common function

示例1:

Javascript

<script>
    const gfg = {
        name: "javascript",
        content: "prototype",
        feature: function () {
            console.log(
                `Help in learning {this.name}. 
                The topic is{this.content}`
            );
        }
    }
 
    // Simple method to feature of gfg object
    gfg.feature();
    console.log()
 
    // Try to bind gfg object property feature
    // to other common function so that it
    // used for later use but it does not
    // happen here
    let b = gfg.feature;
    b();
    console.log()
 
    // Now try to bind object using bind 
    // method 
    // bind method first argument refer
    // object that's why parameter gfg object
    let c = gfg.feature.bind(gfg);
    c();
</script>

注意:将不同的对象绑定到一个公共函数，以便每个对象都可以访问该函数，并将额外的功能绑定到对象上，因此Bind函数接受任意数量的参数。

示例2:

Javascript

<script>
    const gfg = {
        name: "javascript",
        content: "prototype",
    }
 
    const gfg1 = {
        name: "c++",
        content: "inheritance",
    }
 
    const gfg2 = {
        name: "java",
        content: "applet",
    }
 
    // Function which is binding with different object
    function features(param) {
        console.log(`Help in learning {this.name}. 
        The topic is{this.content} and 
         these are help in ${param}`)
    }
 
    // Binding obj1 abd extra functionality
    let bindfunc = features.bind(gfg);
 
    bindfunc("placement");
     
    // Binding obj2
    let bindfunc1 = features.bind(gfg2);
    bindfunc1("placement");
</script>