C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C printf and Scanf C Data type C Token Variable in C Operators in C Comments in C Escape Sequence in C C – Storage Classes C Decision control statement Loop Statement in C Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Static Function In C Sizeof In C Selection Sort In C Scope Of Variables In C Runtime Vs Compile Time In C Random Access Lseek In C Queue Implementation In C Pseudo Code In C Prototype In C Pointer To Pointer In C Pointer Arithmetic In C Passing Array To Function In C Null Character In C Merge Sort In C Macros In C Library Functions In C Memory Leak In C Int In C Goto And Labels In C Fibonacci Series In C Fflush In C Derived Data Types In C Data Types In C Const Vs Volatile In C Character Set In C Character Class Tests In C Calloc In C C Pointers Arrays In C Include In C Clrscr In C C Vs Java String Literals In C Types Of Pointers In C Variables In C Volatile In C Why C Is A Middle Level Language Infix To Postfix Program In C Ceil function in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Armstrong program in C using function Array, Declaring Arrays and Array Initialization Limitations of Inline Function in C Merge and Merge sort with example in C Do-While Loop in C For Loop in C While-Loop in C Difference between while and do-while loop in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures In C How to Avoid Structure Padding in C Use of Structure in C Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples Entry Control Loop in C Exit control loop in C Infinite loop in C Nested loop in C pow() function in C String Handling functions in C Prime Number code in C Factorial Program in C using For Loop Factorial Program in C Using While Loop Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Prime Number Program in C using for Loop While Loop in C programming examples Built-in functions in C Assert() Function C vs Java Strings Call Back Function in Embedded C Else If Ladder fgets() function Ftell() Function getc() function getch() function gets() function Heap Sort Nested if-else statement Pi() Function Positioning of file Write() function abs() function in C Attributes in C C program to find factorial of a number using Recursion Ferror() in c fopen() function in C Fibonacci series program in C using Recursion Formatted Input and output function in C Snake Game in C User Defined Functions in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C C Program to find the Roots of a Quadratic Equation C Switch Statements Difference between rand() and srand() function in C Difference between while and for loop in C Doubly Linked list in C Example of Iteration in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C Integer Promotions in C C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Multiplication table program in C using For loop Nested Loops in C Programming Examples C Program for Mean and Median of an Unsorted Array Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Simple hash() function in C strcat() Function in C Sum of N numbers in C using For loop Use of free() function in C Write a program that produces different results in C and C++ C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Floor() Function in C Free() Function in C How to delete a file in C How to move a text in C Remove an element from an array in C Unformatted input() and output() function in C What are linker and loader in C fork() in C GCD program in C Branching Statements in C Comma Operator in C Control statement in C Double Specifier in C How to create a binary file in C Long int in C Palindrome Number in C Pure Virtual Function in C Run Time Polymorphism in C Types of Array in C Types of Function in C What is a buffer in C What is required in each C Program Associativity of Operators in C Bit Stuffing Program in C Actual and Formal Parameters Addition of two Numbers in C Advantages of function in C Arithmetic Progression Program in C Binomial Coefficient Program in C Difference between Array and List in C Diffie-Hellman Algorithm in C How to convert a number to words in C How to convert a string to hexadecimal in C Difference between If and Switch Statement in C

Difference between rand() and srand() function in C

What is the rand()?

The rand() means random function. This function is used in C. It generates random numbers in the range of 0 to the RAND_MAX. Suppose we generate a game in C using some random number from 1 to 9.

In this case, we can use the rand() function to create a game. In the case of programs, when the rand() function generates without calling the srand() function, the program can produce the same value when it is running. rand() function generates by some algorithm.

This algorithm gives a series of numbers unrelated to each other when the rand() and function are calls.

Example- When we generate the random function between 1 to 9, then we write the function like the below instruction:

Num = rand() % 9 + 1

Syntax:  

int rand(Void);

Parameters – The rand() function does not use any parameters.

Return value - The rand() function returns the pseudo number in RAND_MAX. The range of the return value is between 0 to RAND_MAX.

If we generate 10 random numbers by the C with the help of the rand() function in a loop, then whenever we compile and run the program, the output sequence is always the same. The program is created where the same sequence is in the random numbers.

Program –

#include <stdio.h> 
#include <conio.h> 
int main (void) 
{ 
Printf (“generated random numbers are: “);
for (int i = 0; i < 3; i++) 
printf (“%d”, rand()); 
return 0; } 

Output 

When the first time we generate the code, the output will be –

generated random numbers are: 123 567 456

When the second time we generate the code, the output will be –

generated random numbers are: 123 567 456

When the nth time we generate the code, the output will be –

generated random numbers are: 123 567 456

This is the program using the rand() function. The above program is generated the same sequence of a random number in the output whenever the program run. So the output is the same in every program.

What is srand()?

Strand() is another important function in C. srand() is the in-built function in C. srand() defined by the <stdlib.h> header file in the C program. The argument is passed like a seed.

In the program, if srand() is not called, then rand() seed set. If srand() = srand(1) then the program start. The seed value is used to srand() to generate the different pseudo functions. Any value of the seed is set the develop another starting point.

Syntax – int srand ( unsigned seed );

Parameters - The srand() function use parameter seed. The seed parameter uses to generate the pseudo-random integers.

Return value – The srand() function returns the pseudo-generated random number. This function should be seeded or reseeded. When anyone want to generate a new series of pseudo numbers.

Program –

#include <stdio.h> 
#include <stdlib.h> #include <time.h> 
int main (void)
 { 
 Srand (time (0)); 
Printf (“generated random numbers are: “); 
for (int i = 0; i < 3; i++) 
printf (“%d”, srand()); 
return 0; } 

Output – When the first time we generate the code, the output will be –               

generated random numbers are: 123 567 456

When the second time we generate the code, the output will be –

generated random numbers are: 127 547 436

When the nth time we generate the code, the output will be –

generated random numbers are: 523 467 156

This is the program using srand() function. The above program generates a different sequence of a random number in the output every time program runs.

So the main difference between the rand() and srand() function using C is the rand() function generates the same output every time of program execution; the srand() function does not generate the same result every time of program execution. The syntax, parameter all the values are different in the rand and srand.



ADVERTISEMENT
ADVERTISEMENT