For part of a programming that I'm writing, I want to generate random numbers between the range of -1000 and 1000. My teacher never spent much time on the rand function, and I'm not quite sure how to specify a range like that. Any help would be greatly appreciated. Thanks!

## Recommended Answers

randNum = (rand() % range) + firstNum;

range is the total number you want to generate
firstnum is the beginning number of that range

What Walt P said basically sums it up =)

I took off my answer so you could think a little bit harder for yourself =P

## All 6 Replies

randNum = (rand() % range) + firstNum;

range is the total number you want to generate
firstnum is the beginning number of that range

What Walt P said basically sums it up =)

I took off my answer so you could think a little bit harder for yourself =P

Sometimes it helps to see concrete examples:

``````int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100);  Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100

const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)``````

When you want to look up a function, you can see examples here. Bookmark it if you need to. Its a good reference

Sometimes it helps to see concrete examples:

``````int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100);  Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100

const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)``````

When you want to look up a function, you can see examples here. Bookmark it if you need to. Its a good reference

Thanks! The example worked well! I figured it out now.

Sometimes it helps to see concrete examples:

``````int r1 = rand() ; //random number from [0 , RAND_MAX]
int r2 = rand() % 100; // random number from [0,100);  Note doesn't include 100
int r3 = rand() % 100 + 1; //random number from [1,100]; Note includes 100

const int max = 100;
const int min = -100;
int r4 = rand() % (max - min) + min; // random number between [min,max)``````

When you want to look up a function, you can see examples here. Bookmark it if you need to. Its a good reference

How do i mark a thread solved? I'm relatively new here :p

by the bottom before the text box, there's some text then you can click: Mark this Thread as Solved

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