JavaScript Call Nested Function

Javascript call nested function

    function initValidation()    {        // irrelevant code here        function validate(_block){            console.log( "test", _block );        }            initValidation.validate = validate;    }
    initValidation();    initValidation.validate( "hello" );    //test hello

How to call nested function in javascript?

In general, you can't. The point of defining a function inside another function is to scope it to that function.

The only way for b to be accessible outside of a is if (when you call a) you do something inside a to make it available outside of a.

This is usually done to create a closure, so that b could access variables from a while not making those variables public. The normal way to do this is to return b.

function a() {
  var c = 0;
  function b() {
    alert(c++);
  }
  return b;
}
var d = a();
d();
d();
d();
var e = a();
e();
e();
e();

How to call nested function from outside function

hello is entirely private to the context of each call to batman. You can't call it from anywhere else unless you make it available somehow, for instance by assigning it to a property on the object you're creating by calling batman via new:

function batman(){
    this.hello = function() {
        console.log("hello world!");
    };
}

Example:

var a = new batman();//var b = new batman();//var c = new batman();robin();
function batman(){    this.hello = function() {        console.log("hello world!");    };}
function robin(){    a.hello();}

How to call nested function in javascript

Refer following code snippet. You need to return findval object at all;

( function() {
 function finder(){ 
   var findval = {
       find : function(){
          console.log("call this Function");
       }

   };
   return findval;
 }

 outsidecall = function(){ 
    var findval = finder();
    findval.find();
 }

 outsidecall();
})();

Calling a nested function JavaScript

You just have to return your counter.

function makeCounter() {
  let count = 0;

  function counter() {
    return count++;
  }

  counter.decrease = function () {
    return count--;
  };

  counter.set = function (value) {
    return count = value;
  };
  
  return counter;
}

const myCounter = makeCounter();

console.log(myCounter()); // 0
console.log(myCounter()); // 1
console.log(myCounter.set(42)); // 42
console.log(myCounter()); // 42 (*see why next)
console.log(myCounter.decrease()); // 43 (*see why next)
console.log(myCounter()); // 42

Javascript nested function call always returns value of true

The codes are not equivalent.

In the first example, you're calling f2, then using what it returns to filter.

In the second example, you never call the function; you're returning the uncalled function in the filtering function. Since functions themselves are truthy, it allows all elements, regardless of what the function returns.

To make it equivalent, you need to call the inner function:

. . . 
function(a){
  return (function(b){
    return false;
  })(a); // Add parenthesis to call
}
. . . 

understanding different nested function call

If I understand your question correctly, what's happening is that by adding parentheses with var d = a(); you're actually calling function a. When running your code

function a() {
  var c = 0;
  function b() {
    alert(c++);
  }
  return b();
}

var d = a();
d();

it gives an error, and what happened is that d is not a function, when you assign a() to var d you're assigning the result of a(), which in function a, it will return the result of a, because return b()is actually calling function b which returns the result of function b, so in turn, var d is actually equal to 0 when the code is run. If you want to assign the actual function a to the variable d, just remove the parentheses like this

function a() {
  var c = 0;
  function b() {
    alert(c++);
  }
  return b;
}

var d = a; <-------
d();

And it works just fine.

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