Why does break work in switch blocks but not if-else blocks in C? [closed]

A break that only exited an if statement would not be useful. Consider this code:

if (test)
{
    A;
    break;
    B;
}

Since the break exits the if statement, this is equivalent to:

if (test)
{
    A;
}

So why write the break; and the code after it at all? To be useful here, the break would need to be conditional; it would have to be something like:

if (test)
{
    A;
    if (want to exit)
        break;
    B;
}

But now the break is inside another if, so it would only exit that if, not the outer one. So it cannot do the job of exiting the outer if.

Also, if break exited an if statement, rather than a containing loop or switch, then it would not be useful in loop statements.

break is used in loops (for, while, and do) to exit loops when some condition is reached. For this use, the break statement must be inside an if. For example, a loop for searching for some element in an array would have a form like:

for (int i = 0; i < N; ++i)
    if (array[i] matches conditions)
        break;

Given that a useful break in a for loop must be inside an if statement, a break that terminated an if statement would not be useful. If the break above only exited the if statement, it would not be useful, and the for loop would continue exiting even though we want it stopped.

If you do have a need to exit an if statement, you can do it with goto:

if (test)
{
    A;
    if (error occurs)
        goto EndOfIf:
    B;
}
EndOfIf:

or with an enclosing loop or switch:

switch (0)
{
    default:
    if (test)
    {
        A;
        if (error occurs)
            break;
        B;
    }
}

The break statement works differently in switch blocks and if-else blocks in the C programming language because they are designed to serve different purposes and are structured differently.

Break statement is used to exit a switch block early, while if-else blocks do not have this behaviour since they don't have the concept of "fall-through" like switch blocks. Instead, the program continues executing through the if-else chain, evaluating each condition and executing the corresponding block until one condition evaluates to true or none of the conditions match.

switch (value) {
case 1:
    // Do something if value is 1
    break; // Exit the switch block after handling case 1
case 2:
    // Do something if value is 2
    break;
// ... other cases
default:
    // Do something if none of the cases match
}