How can I generate 4 - digits random number in C?

Question

I'm trying to generate a 4 digits number using C. I think that we are able to use the 'rand' function, however it generates random numbers with random digits, not only 4. We have to generate a 4 - digits number.

Any help? Thanks in advance!

check this for 4digit only http://stackoverflow.com/questions/19051860/generate-random-numbers-with-fixed-digits-length — Francis Saul, Dec 07 '15 at 08:56

score 3 · Answer 1 · edited Dec 07 '15 at 08:52

3

you can use this if it's "randomness" isn't important:

1000+(rand()%9000)

edited Dec 07 '15 at 08:52

Thomas Ayoub

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answered Dec 07 '15 at 08:51

hassan arafat

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I like it. You generate a number between 0 and 8999 and then you add 1000, moving the number to be between 1000 and 9999 – SomethingSomething Dec 07 '15 at 08:53

score 2 · Answer 2 · edited Dec 07 '15 at 09:05

2

Please try this one, i hope it will help you. arc4random uses a better pseudo random number generator than random: it generates a statistically more uniform, less predictable distribution; is based on a larger range of possible numbers. Also, ar4random doesn't need to be initialized as its seed is auto-generated.

E.g. generate numbers :1000~9999

int randomID = arc4random() % 9000 + 1000;

generate numbers :1000~2999

int randomID = arc4random() % 2000 + 1000;

edited Dec 07 '15 at 09:05

Michele Giuseppe Fadda

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answered Dec 07 '15 at 08:53

Mohd Aman

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C does not define the PRNG to be used with `rand()` so the comparison may not be true. OTOH, many `rand()` are weak. – chux - Reinstate Monica Dec 07 '15 at 15:31

How can I generate 4 - digits random number in C?

2 Answers2