Anonymous Functions

What is Anonymous Functions ?

An anonymous functions is a function that was declared without any named identifier to refer to it. As such, an anonymous function is usually not accessible after its initial creation.

Example:

Named function:

function hello() { 
  alert('Hello world'); 
} 
hello(); 

Anonymous function:

In below example, we define an anonymous function that prints a message(“I am anonymous”) to the console. The function is then stored in the txt variable. We can call the function by invoking txt().

var txt = function() { 
  alert('I am anonymous'); 
} 
txt(); 

Example 2: Arguments to the anonymous function.

var msg = function (name) {
	console.log("Hello ", name);
};

msg("RajiniKanth");

Hello RajiniKanth

Use of Anonymous Functions ?

1. Anonymous functions are useful to avoid name collisions and this applies to all languages that support it.
2. JavaScript is a High Order language, which makes it able to pass functions as an argument to other functions. Previously we used to pass the name of the function like this.

function timeOut(){
     console.log(“i will console after 1 sec”)
} 
setTimeout(myFunction(), 1000)

As the Anonymous function does not have a name, we can pass directly as the arguments to other functions. We do not need explicitly declare the function outside the argument. Here it goes like

setTimeout(timeOut() {
     conole.log(“i will console after 1 sec”)    
}, 1000)

1. Anonymous Function is a function that does not have any name associated with it.
2. An anonymous function is not accessible after its initial creation, it can only be accessed by a variable it is stored in as a function as a value. 
3. An anonymous function can also have multiple arguments, but only one expression.