JavaScript value comparison bug

Question

Hello I have this problem that I don't know how to fix. I have this piece of code in JavaScript. There are two console logs that writes variable to console that I later compare if one is bigger than other. Problem is that JavaScript wrongly compare them in if(alarmArray[i].ExtId < offsetTime) even if alarmArray[i].ExtId = 11:42:35 and offsetTime = 11:42:7 the condition is still meet and IF will return true. Is this some kind of JavaScript bug?

for (var i = alarmArray.length - 1; i >= 0; i -= 1) {
        console.log(alarmArray[i].ExtId);    //writes 11:42:37
        console.log(offsetTime);             //writes 11:42:7
        if (alarmArray[i].ExtId < offsetTime) {  
            console.log(alarmArray[i]);  
            alarmArray.splice(i, 1);
        }
    }

Maybe if we had a clue what `alarmArray` or `offsetTime` contained we could be more helpful. — Nicholas Hazel, Jun 11 '15 at 10:08
Well its in the text and next to that code. alarmArray[i].ExtId = 11:42:35 and offsetTime = 11:42:7 its time comparing.There are two console logs that writes those compared values. — Mitre, Jun 11 '15 at 10:10
are those string values? if yes this is the expected behaviour.... — , Jun 11 '15 at 10:11
Look here: [How can I compare two time strings in the format HH:MM:SS?](http://stackoverflow.com/questions/6212305/how-can-i-compare-two-time-strings-in-the-format-hhmmss) — fatrex, Jun 11 '15 at 10:11
Loops take time to run. You're running a loop and expecting the same time to output if I had to guess, but you're coming up fractions offset. — Nicholas Hazel, Jun 11 '15 at 10:12
Yes those are strings but if this is expected shouldnt "11:42:35" still be bigger than "11:42:7"? — Mitre, Jun 11 '15 at 10:12
in string comparison "11:42:3" + any char is lower than "11:42:7", you need to convert the values to date or number to make this work — , Jun 11 '15 at 10:14

score 0 · Accepted Answer · edited May 23 '17 at 12:30

0

You can compare two strings directly if you use the correct format:

HH:MM:SS < HH:MM:SS

But you are trying to compare HH:MM:SS < HH:MM:S which is a wrong format.

Actually, I think the best answer is here: https://stackoverflow.com/a/6212411/3648578

edited May 23 '17 at 12:30

Community

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answered Jun 11 '15 at 10:24

kosmos

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score 0 · Answer 2 · answered Jun 11 '15 at 11:05

Ok its fixed. I forgot add zero to seconds and minutes in function that formate my time.function formatTime(item) { var hour = item.getHours(), min = item.getMinutes(), sec = item.getSeconds(); if (sec <= 9) sec = "0" + sec; if (min <= 9) min = "0" + min; var time = "" + hour + ":" + min + ":" + sec + ""; return time; }

if (sec <= 9) sec = "0" + sec; if (min <= 9) min = "0" + min; was missing in my code

JavaScript value comparison bug

2 Answers2