Home › forums › Using CanvasJS › How to draw an array value and repeat at the end, running real time chart › Reply To: How to draw an array value and repeat at the end, running real time chart
>> what different in for() function between j < count and j < yVal.length, changing two type this condition get two different results
count determines the number of data points to be updated in one go. Because we want to render the entire array in the beginning, we use yVal.length. But after the first render we don't pass it any parameter inside setInterval because of which it defaults to 1 update every second.
>> if I set time = (new Date()).getTime(); and than take time++ for seeking x Axis by time, is it the same as time.setSeconds(time.getSeconds() + 1); in your code ?
time is actually in milliseconds and doing ++ will just increment it by a millisecond and not by one second. Here you have more details.
>> whats yVal[updateCount % yVal.length] mean ? Sorry I can’t get it
Modulo operator (%) is used to wrap around the yVal array once the end is reached. So once the end of array is reached, it gets you back to the first position of the array. Here it is explained with examples.