Java convert any integer to 4 digits

java integer format zero-pad
Cody picture Cody · Oct 11, 2011 · Viewed 28.1k times · Source

This seems like an easy question. One of my assignments basically sends a time in military format (like 1200, 2200, etc) to my class.

How can I force the integer to be converted to 4 digits when it's received by my class? For example if the time being sent is 300, it should be converted to 0300.

EDIT: it turns out i didnt need this for my problem as i just had to compare the values. Thanks

Answer

Alex Abdugafarov picture Alex Abdugafarov · Oct 11, 2011

As simple as that:

String.format("%04d", 300)

For comparing hours before minutes:

int time1 =  350;
int time2 = 1210;
//
int hour1 = time1 / 100;
int hour2 = time2 / 100;
int comparationResult = Integer.compare(hour1, hour2);
if (comparationResult == 0) {
    int min1 = time1 % 100;
    int min2 = time2 % 100;
    comparationResult = Integer.compare(min1, min2);
}

Note:

Integer.compare(i1, i2) has been added in Java 1.7, for previous version you can either use Integer.valueOf(i1).compareTo(i2) or

int comparationResult;
if (i1 > i2) {
    comparationResult = 1;
} else if (i1 == i2) {
    comparationResult = 0;
} else {
    comparationResult = -1;
}

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