if (bytesAvailable > 0) {
ProcessData();
bytesAvailable -= n;
} else {
waitForMoreData();
bytesAvailable = n;
}
Nested ifs
A nested if is an if statement that is the target of another if or else. Nested ifs are very common
in programming. When you nest ifs, the main thing to remember is that an else statement
always refers to the nearest if statement that is within the same block as the else and that is
not already associated with an else. Here is an example:
if(i == 10) {
if(j < 20) a = b;
if(k > 100) c = d; // this if is
else a = c;
// associated with this else
}
else a = d;
// this else refers to if(i == 10)
As the comments indicate, the final else is not associated with if(j<20) because it is not
in the same block (even though it is the nearest if without an else). Rather, the final else
is associated with if(i==10). The inner else refers to if(k>100) because it is the closest if
within the same block.
The if-else-if Ladder
A common programming construct that is based upon a sequence of nested ifs is the
if-else-if ladder. It looks like this:
if(condition)
statement;
else if(condition)
statement;
else if(condition)
statement;
.
.
.
else
statement;
The if statements are executed from the top down. As soon as one of the conditions controlling
the if is true, the statement associated with that if is executed, and the rest of the ladder is
bypassed. If none of the conditions is true, then the final else statement will be executed.
The final else acts as a default condition; that is, if all other conditional tests fail, then the
Search WWH :
