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"The goto statement provides an explicit jump, but use it wisely to avoid unstructured code."

What is the goto Statement?

The goto statement is used to transfer control to a labeled statement within the same function.

Syntax of goto

goto label;
...
label:
// Statements

How goto Works

• A label is defined using an identifier followed by a colon (:).
• The goto statement transfers program execution to the labeled statement.
• Note: The label must be within the same function.

Example: Using goto for Conditional Jumps

#include <stdio.h>

int main() {
int num;
printf("Enter a positive number: ");
scanf("%d", &num);

if (num < 0) {
	goto error;
}

printf("You entered: %d\n", num);
return 0;

error:
printf("Error: Negative numbers are not allowed.\n");
return 1;
}

Types of Jumps Using goto

Example: Forward Jump Using goto

#include <stdio.h>

int main() {
printf("Start of program\n");
goto skip;
printf("This line is skipped.\n");

skip:
printf("End of program\n");
return 0;
}

Example: Backward Jump Using goto

#include <stdio.h>

int main() {
int count = 1;

repeat:
printf("Count: %d\n", count);
count++;

if (count <= 5) {
	goto repeat;
}

return 0;
}

When to Use goto

• When breaking out of deeply nested loops.
• For error handling to jump to a cleanup section.
• For improving readability in certain complex scenarios.

When to Avoid goto

• When it creates "spaghetti code" that is hard to follow.
• When structured alternatives (loops, functions, conditionals) can be used.
• When it makes debugging more difficult.

Example: Using goto for Error Handling

#include <stdio.h>

int main() {
FILE *file = fopen("data.txt", "r");

if (file == NULL) {
	goto error;
}

printf("File opened successfully.\n");
fclose(file);
return 0;

error:
printf("Error: Could not open file.\n");
return 1;
}

Alternative to goto

Instead of goto, structured programming constructs like loops and functions should be used.

Using Loops Instead of goto

#include <stdio.h>

int main() {
for (int count = 1; count <= 5; count++) {
	printf("Count: %d\n", count);
}
return 0;
}

Best Practices for Using goto

• Use it only when necessary (e.g., error handling, breaking multiple loops).
• Keep labels meaningful and easy to follow.
• Avoid excessive goto jumps within the same function.

Conclusion

The goto statement in C provides direct control over program flow, but it should be used carefully to maintain code readability and maintainability.

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