Javascript Question posted in
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Javascript – Anonymous Functions Vs Classic Function

I’m not able to figure out the reason for this behavior, can any one help me understand

  let counter= (function (){
    let count = 0;
    return function() {
        count+=1;
        return count;
    }
})()

for (let i = 0; i< 3; i++){
    console.log(counter());
}

This prints an output of

 1
 2
 3

Where as the below code

 function increment() {
    let count = 0;
    return function() {
        count+=1;
        return count;
    }
}

for (let i = 0; i< 3; i++){
    console.log(increment()());
}

Prints 1 1 1 1

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2

Answers


  1. Chosen as BEST ANSWER
    0

    Is it because let counter is pre-initialized with a function where count = 1 ; But in the other case, as the function is called every time, it's resetting the count to 0


  2. 0

    In the first example, the closure is created once and reused, so the state (count) is maintained across calls.

    In the second example, a new closure (and hence a new count variable) is created each time increment() is called, so the state is not shared across the loop iterations.

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