1、if语句
#include <stdio.h> int main() { int x; scanf("%d", &x); int f=0; if ( x < 0 ) { f = -1; } else if ( x == 0 ) { f = 0; } else if ( x >5 ) { f = 2 * x; } else { f = 3*x; } printf("%d ", f); return 0; }
2、switch..case语句
#include <stdio.h> int main() { printf("输入成绩（0-100）"); int grade; scanf("%d", &grade); grade /=10; switch ( grade ) { case 10: case 9: printf("A "); break; case 8: printf("B "); break; case 7: printf("C "); break; case 6: printf("D "); break; default: printf("F "); break; } return 0; }
#include <stdio.h> int main() { printf("请输入月份："); int month; scanf("%d", &month); switch ( month ) { case 1: printf("January "); break; case 2: printf("February "); break; case 3: printf("March "); break; case 4: printf("April "); break; case 5: printf("May "); break; case 6: printf("June "); break; case 7: printf("July "); break; case 8: printf("August "); break; case 9: printf("September "); break; case 10:printf("October "); break; case 11:printf("November "); break; case 12:printf("December "); break; } return 0; }