CODEWITHSUNDEEP
javascriptjquery
Virge Assault
Virge Assault

Reputation: 1396

Updating a variable with a Javascript function error

I'm having trouble updating the value of a variable q with a javascript function. I have a timer that starts when "play" is pressed, and then continuously fires the current demand function

$(document).ready(function(){

  $("#main_video").on(
    "timeupdate", 
    function(event){
      currentDemand(this.currentTime);
    });
}); 

// Initiate Demand
var q = 0;

function currentDemand(currentTime){

    console.log(currentTime);

    if ( 0 <= currentTime < 10) {
        q === 0;
    }
    else if ( 10 <= currentTime < 12.5 || 57.5 <= 60) {
        q === 1;
    }
    else if ( 12.5 <= currentTime < 17.5 || 55 <= currentTime < 57.5) {
        q === 2;
    }
    else if ( 17.5 <= currentTime < 20 || 50 <= currentTime < 55) {
        q === 3;
    }
    else if (20 <= currentTime < 25 || 47.5 <= currentTime < 50) {
        q === 4;
    }
    else if ( 25 <= currentTime < 27.5 || 45 <= currentTime < 47.5 ) {
        q === 5;
    }
    else if ( 27.5 <= currentTime < 32.5 || 42500 <= currentTime < 45 ) {
        q === 6;
    }
    else if ( 32.5 <= currentTime < 35 || 40 <= currentTime < 42.5 ) {
        q === 7;
    }
    else if ( 45 <= currentTime < 47.5 ) {
        q === 8;
    }

    console.log(q);
    $("#currentDemand").text(q);
}

currentTime is logging correctly at values that should put it in the intervals, but q is not being set. It probably has something to do with the scope, I just can't figure out how to fix it so that q is updated correctly and put into the #currentDemand div.

How can I set q to update?

Upvotes: 0

Views: 47

Answers (4)

Barmar
Barmar

Reputation: 780724

This is not the correct way to test if currentTime is between two values:

else if ( 10 <= currentTime < 12.5 || 57.5 <= 60) {

It's parsed as if you'd written:

else if ( ((10 <= currentTime) < 12.5) || (57.5 <= 60)) {

Since 57.5 is always less than 60, the entire expression will always be true. But 10 <= currentTime < 12.5 is also always true, because 10 <= currentTime is either true or false, and they're converted to 1 or 0 when comparing with another number. And both 1 and 0 are less than 12.5.

It should be written as:

else if ( (10 <= currentTime && currentTime < 12.5) || (57.5 <= currentTime && currentTime < 60) ) {

Upvotes: 2

Zakaria Acharki
Zakaria Acharki

Reputation: 67505

You should use one equal = for assignment purpose, the both double == and triple === equals are used for comparaison.

Also you should separate your condition to looks like :

if ( currentTime >= 0 && currentTime < 10) {
    q = 0;
}
else if ( currentTime >= 10 && currentTime < 12.5 || 57.5 <= 60) {
//__________________________________________________^__________^ 
//this condition should be removed because it return always true
    q = 1;
}
else
.....

Hope this helps.

Upvotes: 1

Nestoraj
Nestoraj

Reputation: 762

To assign a value, you must only use one = if you use == or === are comparative. More info here:

Assigment

Comparative

Upvotes: -1

Morifen
Morifen

Reputation: 126

q = whatevernumber;

not q === whatevernumber, which returns a boolean

Upvotes: 0

Related Questions