Determine if a number is even or odd
#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <stdlib.h> // system function required
int main(){ int a;
while (1) // infinite loop { printf("Please enter an integer:\n"); scanf("%d", &a);
if (a % 2 == 0) { printf("%d is even\n", a); } else { printf("%d is odd\n", a); }
printf("Press any key to continue...\n"); getchar(); // consume newline getchar(); // wait for user key press
system("cls"); // clear screen; }
return 0;}The C language program determines the parity of a number,translated into natural language English:
#define _CRT_SECURE_NO_WARNINGS — DisablesVisual Studiospecific security warnings (e.g.,scanfmay be unsafe). Other compilers generally do not require this.
#include <stdio.h> ——- Standard input/output library, used forprintf,scanfand other functions.
#include <stdlib.h> // system function required —- Standard library header file, includes system functions likesystem()to execute system commands (e.g., clear screen).
int main() —— Program entry point, marks the start of the main function
{
int a; —— Defines an integer variablea, used to store the user input number
while (1) ——– Infinite loop, the program will continue running until manually terminated
{
printf(“Please enter an integer:\n”); —- Displays a prompt to the user to enter an integer
scanf(“%d”, &a); ——– Reads the user input integer and stores it in variablea
if (a % 2 == 0) ——- Ifamodulo 2 equals 0
{
printf(“%d is even\n”, a); —- Outputsais even message
}
else —– Ifais not divisible by2, remainder is not 0, it is odd
{
printf(“%d is odd\n”, a); —— Outputsais odd message
}
printf(“Press any key to continue…\n”); ——- Prompts the user to press any key to continue the program
getchar(); // Consume newline ———- Reads and discards the newline left by the previous input to avoid interference with the next input
getchar(); // Wait for user key press ——– Waits for the user to press any key to continue program execution
system(“cls”); // Clear screen; ——– Calls the system command to clear the screen (only applicable toWindows)
}
return 0; ———– Program ends normally and returns0to the operating system
}
Program output:
