CODEWITHSUNDEEP
javascriptjquery
Phillip Musumba
Phillip Musumba

Reputation: 71

SetInterval() with "if" condition in js function

I would like to continuously call the function below using setInterval() but only if the condition in the if statement evaluates to true. Note: The function is global.

function view_stack(){
    if(my_stack.size() > 0){
        document.getElementById("stack_visual").innerHTML = my_stack.view();
    } else {
        swal("Ohhhh Noes", "There are no items in the stack!", "error");
    }
}

Is there a way I can achieve it?

Upvotes: 3

Views: 19735

Answers (3)

Eyalchu
Eyalchu

Reputation: 33

You can simply nest your function within a setTimeout nested within a while loop.

function view_stack(){

  while(my_stack.size() > 0){
  
    setTimeout(() => {
    
      document.getElementById("stack_visual").innerHTML = my_stack.view();
    
    ), 1000} //for a second rhythm.
  
  }
  
  swal("Ohhhh Noes", "There are no items in the stack!", "error");

}

this way the function will work only if "true" and still have control over the rhythm it works.

Upvotes: 1

Tomalak
Tomalak

Reputation: 338168

Make it so that your function does nothing when there is nothing to do. That way you can simply keep the interval running.

Effectively your code already is written like that, I would rearrange it like this:

function view_stack(){
    if(my_stack.size() === 0) return;
    document.getElementById("stack_visual").innerHTML = my_stack.view();
}

setInterval(view_stack, 1000);

The more elegant solution would be event-based, i.e. whenever my_stack changes, update the view.

Upvotes: 8

Nick Parsons
Nick Parsons

Reputation: 50684

You could put an if statement in the setInterval function like so:

setInterval(function() {
  if(my_stack.size() > 0) {
    view_stack();
  }
}, 1000/60);

So, only if my_stack.size() > 0 it will then call the view_stack() function.

Note setInterval() is triggered 60 times per second.

Upvotes: 2

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