Switch statement within while loop in C -
there several postings concerning switch statements within while loops, except fact none of them done in c, @ least i've seen. c++ can create boolean expressions, i'm aware of, not in c. have while loop contains switch control. however, when write break statements within switch, goes beginning of loop , makes program run forever. ignore functions use, work sure. need clarification on handling of nesting. thanks!
here main.c: while(1) { printf("0) exit\n1) list tasks\n2) add task\n"); printf("3)delete task\n4) add task file\n"); printf("what do?\n"); fgets(buf1, 50, stdin); p = atoi(buf1); switch(p) { case 0: break; case 1: printtasklist(ptasklist); break; case 2: printf("enter task name: "); fgets(buf2,100,stdin); printf("enter task priority: "); fgets(buf3,100,stdin); printf("enter task start date: "); fgets(buf4,50,stdin); ptask = maketask(buf2,buf4,buf3); addtasktoend(ptasklist,ptask); break; case 3: printtasklist(ptasklist); printf("what task delete? "); fgets(buf6,50,stdin); tasknum = atoi(buf6); removetask(ptasklist,tasknum); break; case 4: printf("enter filename "); fgets(buf7,50,stdin); break; default: printf("error: %d: incorrect menu option\n", p); } }
break; exit out of nearest enclosing switch or loop. jump 2 levels, you'll have use dreaded goto, or reorganize return accomplish desired semantics.
while(1) { switch(x) { case 0: goto endwhile; } } endwhile: ; or
void loop() { while(1) { switch(x) { case 0: return; } } } //... loop(); //... you can totally use boolean expression in c. use int.
int quit = 0; while(!quit) { switch(x) { case 0: quit = 1; break; } } c has boolean data type, if want it.
#include <stdbool.h> bool quit = false; while(!quit) { switch(x) { case 0: quit = true; break; } } and 1 more option, totally insane.
#include <setjmp.h> jmp_buf jbuf; if (!setjmp(jbuf)) while(1) { switch(x) { case 0: longjmp(jbuf, 1); } }
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