How to control number display format using Javascript?-CodePudding

I have a Javascript function that displays a time counter as the following : 0:0 and 0:1. But I actually want it to be displayed like this : 00:00 and 00:01.

Here is the code :

var interval = null;
var time = 0
function increaseTimer() {
    // increase and print timer
    time  
    console.log(new Date()   ' '   'timer: '   parseInt(time / 60, 10)   ':'   parseInt(time % 60, 10))
    // condition of a process
    if (time % 5 == 0) {
        // some process
    }
    // stop simulation after 30s
    if (time == 30) {
        clearInterval(interval)
    }
}

I call this function with interval variable : interval = setInterval(increaseTimer, 1000)

What should I change in my code to make it work ? Thanks in advance.

CodePudding user response：

var interval = null;
var time = 0
function increaseTimer() {
    // increase and print timer
    time  
    let prefix = parseInt(time / 60, 10)
    let postfix = parseInt(time % 60, 10)
    prefix = prefix <= 9 ? "0"   prefix.toString() : prefix.toString();
    postfix = postfix <= 9 ? "0"   postfix.toString() : postfix.toString();
    console.log(new Date()   ' '   'timer: '   prefix    ':'   postfix )
    // condition of a process
    if (time % 5 == 0) {
        // some process
    }
    // stop simulation after 30s
    if (time == 30) {
        clearInterval(interval)
    }
}