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When we are playing a quiz there is timer running for every question. How can we create this type of timer using javascript?

20th Jun 2018, 5:02 AM
Dinesh Kumar
Dinesh Kumar - avatar
2 Respuestas
20th Jun 2018, 5:45 AM
Calviղ
Calviղ - avatar
+ 5
This is mostly a conceptual answer so that others can deliver code / work with it / use another idea. JS is event-driven, and only updates the DOM/display when you give up the main thread, so strategies used in other languages (like a tight loop waiting for the time to change, or sleeping for 1 second) would just hang the browser. In JS, if you want something to happen later, send a message using the event system, then drop off the end of your function so events run. // onload is an event! document.onload = function { // set a message 1000ms from now setTimeout(updateCounter, 1000); // give up control, events will run } // Nothing happens in your code for 1000ms (the engine is busy handling events though) // JS fires your event 1000ms later and runs this function function updateCounter() { ...decrement the counter ...update a DOM element if the counter is above 0: setTimeout(updateCounter, 1000) // give up control, events will run again }
20th Jun 2018, 5:37 AM
Kirk Schafer
Kirk Schafer - avatar