set-interval and clear-interval inside for loop

Question

I have a set-interval function inside a for loop and when inside the set-interval function if it meets a criteria give an alert and clear the interval. Below is my code but its not working can anyone tell what the mistake here.

var timeCheck = 0;
function matchTime() {
    for (var i=0;i<timers.length;i++) {
        timeCheck = setInterval(function () {
            var theDate = new Date(timers[i][0]*1000); 
            var now = new Date(); 
            if ( (now.getFullYear() === theDate.getFullYear()) && (now.getMonth() === theDate.getMonth()) ) {
                if ( (now.getDate() === theDate.getDate()) && (now.getHours() === theDate.getHours()) ) {
                    if ( now.getMinutes() === theDate.getMinutes() && (now.getSeconds() === theDate.getSeconds()) ) { alert("its Time for "+timers[i][1]); stopCheck(); }
                }
            }
        }, 10);
    }
}

function stopCheck() { clearInterval(timeCheck); }

Thanks.

What I am trying to solve is : I need to get an alert every-time when the local time matches the time in the timers array (column 0; timers[count][0]). The array is already sorted
timers.sort(function(a,b) { return a[0] - b[0]; });

Answer 1

It seems like you have your logic backwards. You want to alert the user every time the current time is equal to one of the times in timers, right? Why not use setInterval() and skip the for() loop altogether? If they are already sorted, this works just fine. Also, it seems one if() would do with a much simpler "compare time by second" method.

I slowed down the process in this demo to make it obvious.

Demo:

Script:

var timers = [
        [new Date( ( new Date() ).getTime() + 3000),'party!'], 
        [new Date( ( new Date() ).getTime() + 6000), 'sleep']
    ],
    timer = setInterval( checkTime, 300 );

function checkTime() {
    if( timers.length ) {
        if ( parseInt( timers[0][0].getTime() / 1000 ) 
            == parseInt( new Date().getTime() / 1000 ) ) {

            //alert here
            document.getElementById( 'result' ).insertAdjacentHTML(
                'beforeEnd',
                timers[0][0] + ": " + timers[0][1] + '<br />'
            );
            timers.shift();
        };
    } else {
        clearInterval( timer );
    };
};

HTML:

Wait 3 seconds...
<div id="result"></div>

Answer 2

perhaps:

var timeCheck = {};
function matchTime() {
   for (var i=0;i<timers.length;i++) {
      timeCheck[i] = setInterval(function () {
        var theDate = new Date(timers[i][0]*1000); 
        var now = new Date(); 
        if ( (now.getFullYear() === theDate.getFullYear()) && (now.getMonth() === theDate.getMonth()) ) {
            if ( (now.getDate() === theDate.getDate()) && (now.getHours() === theDate.getHours()) ) {
                if ( now.getMinutes() === theDate.getMinutes() && (now.getSeconds() === theDate.getSeconds()) ) { alert("its Time for "+timers[i][1]); stopCheck(i); }
            }
        }
    }, 10);
    }
}

 function stopCheck(i) { clearInterval(timeCheck[i]); }

or perhaps:

var timeCheck = 0;
function matchTime() {
  var timeCheck = setInterval(function () {
    for (var i=0;i<timers.length;i++) {
        var theDate = new Date(timers[i][0]*1000); 
        var now = new Date(); 
        if ( (now.getFullYear() === theDate.getFullYear()) && (now.getMonth() === theDate.getMonth()) ) {
            if ( (now.getDate() === theDate.getDate()) && (now.getHours() === theDate.getHours()) ) {
                if ( now.getMinutes() === theDate.getMinutes() && (now.getSeconds() === theDate.getSeconds()) ) { alert("its Time for "+timers[i][1]); stopCheck(i); }
            }
        }
    }
   }, 10);
}

 function stopCheck(i) { clearInterval(timeCheck); }