My Switch/case ends early, any ideas why? thank you

This is a discussion on My Switch/case ends early, any ideas why? thank you within the C Programming forums, part of the General Programming Boards category; well guys and gals, my problem is this, im pretty new to programming but i was pretty confident that this ...

  1. #1
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    Feb 2011
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    My Switch/case ends early, any ideas why? thank you

    well guys and gals, my problem is this, im pretty new to programming but i was pretty confident that this code would work, because the individual parts worked separately just fine... everything was going great, then when it got to the line with append(ap) it started the while loop all over.
    Code:
    #include <stdio.h>
    
    void append(char an);
    
    int main(){
    	int choice1;
    	int choice2;
    	char ap;
    	printf("_________________________________________________________________________________________________\n\n\n\n");
    	
    	printf("Would you like to check inventory or update inventory?");
    	while(1){
    	printf("\n\n[1] check\n[2] update\n");
    	scanf("%d", &choice1);
    	switch (choice1){
    		case 1:
    			printf("\n this part hasn't been made yet");
    			break;
    		case 2:
    			printf("\nWould you like to add a new item or change an existing item?");
    			printf("\n\n[1] add\n[2] change\n");
    			scanf("%d", &choice2);
    			switch (choice2){
    				case 1:
    					printf("\nEnter the item you would like to add.");
    					ap=getchar();/*it breaks here, goes back to original switch(choice1), and then carries out append(ap for whatever you type even though it's no longer on this part of the program, any ideas?)*/
    					append(ap);
    					break;
    				case 2:
    					printf("\nnot yet made");
    					break;
    				default:
    					printf("\ninvalid entry, please re-enter:");
    					break;
    				}
    			break;
    		default:
    			printf("\ninvalid entry, please re-enter:");
    			break;
    		}
    	}
    	return 0;
    	}
    
    void append(char an){
    	FILE *f;
    	f=fopen("temp.txt", "a");
    	fprintf(f, "%c", an);
    	fclose(f);
    	}
    anyway i tried for a really long time to figure it out, but to no avail. so if anyone out there know what i did wrong, your help would be greatly appreciated. thankyou!

  2. #2
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    You have an extraneous break; statement at the exit of the inner switch.

  3. #3
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    Feb 2011
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    Unhappy

    nope still doesnt work. no matter what i do to the code it cuts out what ever's after ap=getchar(); and moves on to what ever is next so i guess that's the problem, but i cant see the problem in those two or three line. 8 (

  4. #4
    cas
    cas is offline
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    When you have scanf("%d", &choice2), you're asking the user to enter a number; but what he does is type in a number and then hit enter. scanf() reads the number, but leaves the newline (from the user hitting enter) hanging around, waiting to be read. So when you have your getchar() call, it sees the newline and reads it. You perceive it as skipping the call, but it doesn't. It just doesn't need to wait around for you to type something in because you already did.

    C input can be very messy. Probably the quickest way to get around your problem is to add a getchar() after your scanf(). There is no need to assign its return value to anything because you're just eating a newline.

    This is fragile and assumes the user input will be in a specific format, but that's the road you go down when you're using scanf().

  5. #5
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    that makes sense, thank you so much

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