THE GOTO STATEMENT in C Programming

THE  GOTO STATEMENT:

        The goto statement is used to transfer the control in a program from one point to another point unconditionally. This is also called unconditional branching.

The syntax of the goto statement is:

goto label;

       Where label is a valid identfier used in programming languague ‘C’ to indicate the destination where a control can be transferred. The syntax of label is:

label:

      The various ‘case’ statements in a switch construct also serve as labels used to transfer execution control.

      The goto statement can be used in a program in two ways. These are:

• Conditional Goto 
• Unconditional Goto

Conditional Goto:

     The conditional goto statement is used to transfer the control of execution from one part of the program to another part of the program unde a given condition.

For example:

#include<stdio.h>

main()   {

int a, b;

printf("Enter first number: ");

scanf("%d", &a);

printf("Enter second number: ");

scanf("%d", &b);

if(a > b)

goto output1;

else

goto output2;

output1:

printf("Larger value %d\n", a);

goto end;

output2:

printf("Larger value %d\n", b);

end: ;    }

Output:

Uncontitional Goto:

       Unconditional goto statement to used to transfer the  control from one part of the program to the other part without any condition. Normally, a good programmer does not like to use the unconditional goto statements in a program because it may lead to infinite looping as seen in the following program segment.

main()  {

200:

printf(“Unconditional goto \n);

goto 200;    }

Goto statement used in a for loop:

#include<stdio.h>

main()  {

int i, value;

for(i=0; i <= 10; i++)   {

printf("Enter a number: ");

scanf("%d", &value);

if (value <=0)  {

printf("Error\n");

printf("Zero or negative value found\n");

goto error;  }}

error:

return 0;   }

Output:

Goto statement used within a do-while loop:

#include<stdio.h>

main()  {

int i=0, value;

do  {

printf("Enter any number:");

scanf("%d", &value);

if (value <= 0)  {

printf("Error:");

printf("\nZero or negative value found\n");

goto error;  }

i++; }

while(i <= 10);

error:

return 0; }

Output: