about 7 years ago
Found a really good example that explains the differences among bind, call and apply.
Both call and apply 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"
The difference is that apply can take in an array as the parameters but call has to list them individually:
call(obj, 'arg1', 'arg2', 'arg3');
var args = ['arg1', 'arg2', 'arg3'];
apply(obj, args);
bind only attaches this with a function but id does not execute the function:
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"
You can also pass parameters to bind:
bind(obj, arg1, arg2 ,arg3);
bind is often used to express the intention of "this function is invoked with a particular this".
