[简洁抽象]5 Repetition.pptVIP

5. Repetition 5-1 Concept of a Loop 5-2 Loops in C C has three loop statement: the while, the for, and the do….while. The first two are pretest loops, and the last is a post-test loop. 5-2-1 the While Loop while (expression) while (expression) statement { statement 1 statement 2 - statement n } Flow of while statement This program prints a series of numbers. To keep from running off the end of one line, it adds a test to write a newline when ten numbers have been written. main( ) //no newline { int num, lineCount, i; printf(“Enter an integer between 1 and 100: ”); scanf(“%d”, num); i=1; while (i=num) { printf(“%4d”, i); i++; } } main( ) //with newline { int num, lineCount, i; printf(“Enter an integer \n”); scanf(“%d”, num); i=1; lineCount = 1; while (i=num) { printf(“%4d”, i); i++; if (lineCount10) lineCount++; else { printf(“\n”); lineCount=1; } } } main( ) { int num, lineCount, i; printf(Enter an integer between 1 and 100: ); scanf(%d, num); i=1; lineCount = 1; while (i=num) { printf(%4d, i); if (i%10==0) printf(\n); i++; } } 求从1～N个数的累加和。 main( ) { int num, i, sum; printf(“please enter how many numbers you want to sum.”); scanf(“%d”, num); sum=0; i=1; while ( i=num) { sum+=i; i++; } printf(“ the sum is %d\n”, sum); } 从键盘读入任意多个整数，以EOF （Ctrl+Z）作为结束标志，求这些数的累加和. 必须有 #includestdio.h #include stdio.h main() { int x, sum; sum = 0; printf (“Enter your numbers: ^Z to stop.\n”); while (scanf (“%d”, x) != EOF)