C stdlib srand() Function
Example
Display 10 random numbers between 1 and 100:
// Initialize the randomizer using the current timestamp as a seed
// (The time() function is provided by the <time.h> header file)
srand(time(NULL));
// Generate random numbers
for (int i = 0; i < 10; i++) {
int num = rand() % 100 + 1;
printf("%d ", num);
}
Definition and Usage
The srand() function initializes the rand() function with a seed. The seed specifies which sequence of numbers the rand() function will follow. This means that the same seed will always result in the same sequence of random numbers.
The srand() function is defined in the <stdlib.h> header file.
Syntax
srand(unsigned int seed);Parameter Values
| Parameter | Description |
|---|---|
| seed | A number that specifies which sequence of numbers the rand() function will follow. |
More Examples
Example
Display the same sequence of random numbers twice:
// Initialize the randomizer with a fixed value
srand(10000);
// Generate 5 random numbers
for (int i = 0; i < 5; i++) {
int num = rand() % 100 + 1;
printf("%d ", num);
}
printf("\n");
// Initialize the randomizer with the same value
srand(10000);
// Generate 5 random numbers
for (int i = 0; i < 5; i++) {
int num = rand() % 100 + 1;
printf("%d ", num);
}
