Keep For Loop From Executing In Javascript

Currently for loop gets executed till the end even though the function it calls hasn't finished executing. I want to make it such that, when startloop function is called until it i

Solution 1:

A for loop will not wait for your task. To achieve this task, you will have to use recursion.

Logic:

• Call a function and pass a callback in it.
• On execution completion, run passed callback.
• Now since we have to chain same function again and again, pass same callback to next iteration again and have a check(threshold limit) and stop on breach.

var count = 0functiontest1(i, cb){
  console.log("In Test " + i)
  if(i < 10)
    setTimeout(cb.bind(null, ++count, cb), 2000)
}


test1(count, test1)

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Explanation:

My approach mimics behaviour of a do..while loop. It has 4 parts:

1. Initialisation: This will initialise the iterator variable. This variable will be use to check for termination condition and to check the current iterator's value. In my Case: count = 0
2. Execution of Code block: This will execute the code defined inside {...}. In my case: test1(count, test1)
3. Termination condition: This check if next iteration should be performed or not? In my case: if(i<10). If condition is satisfied, start next iteration: setTimeout(cb.bind(null, ++count, cb), 2000)
4. Increment Value: This updated value of iterator to point to next value. In my case: ++count

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This is the final JSFiddle

Solution 2:

I think that the problem going to be with your for loop. startLoop function always going to get the xObj.length-1.

You can read more about this problem: JavaScript closure inside loops – simple practical example

The variable i, within each of your anonymous functions, is bound to the same variable outside of the function.

Solution with ES6 let feature:

for (let i = 0; i < xObj.length; i++) {
  console.log("for loop running " + i);

  startLoop(i);

  console.log("outside loop func");

}

Solution without ES6:

var funcs = [];

for (var i = 0; i < xObj.length; i++) {
  funcs[i] = startLoop(i);
}

for (var i = 0; i < xObj.length; i++) {
  console.log("for loop running " + i);

  funcs[i]();

  console.log("outside loop func");

}