The if-else Statements

The general syntax of the if statement is as follows:

if (expression) {
    statement1;
}

If the expression evaluates to true, statement1 is executed. If expression is false then nothing is executed and the program execution picks up after the ending curly brace (}). The following diagram shows the flow of control:

To provide for two-way selection an if statement may add an else option.

if (expression) {
    statement1;
}
else {
    statement2;
}

If the expression evaluates to true, the statement is executed. In an if-else statement, if the expression is false then statement2 would be executed. The following flowchart illustrates the flow of control.

The expression being tested must always be placed in parentheses. This is a common source of syntax errors.