goto control instruction in C

goto' Statement in C language. goto is a jumping statement in c language, which transfer the program's control from one statement to another statement (where label is defined). goto can transfer the program's within the same block and there must a label, where you want to transfer program's control.

A goto statement in C programming provides an unconditional jump from the 'goto' to a labeled statement in the same function.

NOTE − Use of goto statement is highly discouraged in any programming language because it makes difficult to trace the control flow of a program, making the program hard to understand and hard to modify. Any program that uses a goto can be rewritten to avoid them.

Syntax

The syntax for a goto statement in C is as follows −

goto label;
..
.
label: statement;

Here label can be any plain text except C keyword and it can be set anywhere in the C program above or below to goto statement.

Flow Diagram

Example:

// Program to calculate the sum and average of positive numbers 
// If the user enters a negative number, the sum and average are displayed.

# include <stdio.h>

int main()
{

    const int maxInput = 5;
    int i;
    double number, average, sum=0.0;
    
    for(i=1; i<=maxInput; ++i)
    {
        printf("%d. Enter a number: ", i);
        scanf("%lf",&number);

        if(number < 0.0)
            goto jump;

        sum += number;
    }

    jump:
    average=sum/(i-1);
    printf("Sum = %.2f\n", sum);
    printf("Average = %.2f", average);

    return 0;
}

Output

1. Enter a number: 3
2. Enter a number: 4.3
3. Enter a number: 9.3
4. Enter a number: -2.9
Sum = 16.60