Question

In my iPhone app I need to round an integer to the nearest multiple of 5.

E.g. Round 6 to = 10 and round 23 to = 25 etc

Edit

I forgot to say, I only want to round up! In all situations, so 22 would round up to 25 for example.

Answer 1

If you want to always round up, you can use the following:

int a = 22;
int b = (a + 4) / 5 * 5; // b = 25;

If a can be a float, you should add a cast to int as follows:

int b = ((int)a + 4) / 5 * 5; // b = 25;

Note that you can use the function ceil to accomplish the same result:

int a = 22;
int b = ceil((float)a / 5) * 5; // b = 25;

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Old Answer:

To round to the nearest multiple of 5, you can do the following:

int a = 23;
int b = (int)(a + 2.5) / 5 * 5;