javascript的call、apply和bind[stackoverflow]

They all attach this into function (or object) and the difference is in the function invocation (see below).
call attaches this into function and executes the function immediately:

var person = {  
  name: "James Smith",
  hello: function(thing) {
    console.log(this.name + " says hello " + thing);
  }
}

person.hello.call(person, "world"); // output: "James Smith says hello world"

bind attaches this into function and it needs to be invoked separately like this:

var person = {  
  name: "James Smith",
  hello: function(thing) {
    console.log(this.name + " says hello " + thing);
  }
}

var helloFunc = person.hello.bind(person);
helloFunc("world");  // output: "James Smith says hello world"

or like this:

...    
var helloFunc = person.hello.bind(person, "world");
helloFunc();  // output: "James Smith says hello world"

apply is similar to call except that it takes an array-like object instead of listing the arguments out one at a time:

function personContainer() {
  var person = {  
     name: "James Smith",
     hello: function() {
       console.log(this.name + " says hello " + arguments[1]);
     }
  }
  person.hello.apply(person, arguments);
}
personContainer("world", "mars"); // output: "James Smith says hello mars", note: arguments[0] = "world" , arguments[1] = "mars"                         

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edited Apr 28 at 7:52