how to generate a random long with 4 digits in java?

Question

how to generate a long that is in the range of [0000,9999] (inclusive) by using the random class in java? The long has to be 4 digits.

score 52 · Accepted Answer · answered Nov 07 '15 at 00:39

52

If you want to generate a number from range [0, 9999], you would use random.nextInt(10000).

Adding leading zeros is just formatting:

String id = String.format("%04d", random.nextInt(10000));

answered Nov 07 '15 at 00:39

Grogi

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It's in the previous answer, but don't forget: `Random random = new Random();` – CodeFinity Dec 22 '21 at 13:24
@CodeFinity I don't see how anyone can forget to create the Random object.lol – Ojonugwa Jude Ochalifu Jan 06 '22 at 16:49
Here what is mean by "%04", Also what can i do If I want to omit the 0 – Feezan Khattak Apr 21 '22 at 09:47

score 11 · Answer 2 · answered Nov 07 '15 at 00:39

A Java int will never have leading 0(s). You'll need a String for that. You could use String.format(String, Object...) or (PrintStream.printf(String, Object...)) like

Random rand = new Random();
System.out.printf("%04d%n", rand.nextInt(10000));

The format String %04d is for 0 filled 4 digits. And Random.nextInt(int) will be [0,10000) or [0,9999].

how to generate a random long with 4 digits in java?

2 Answers2