If Selection Statements used in JAVA

The selection statements allow to choose the set of instructions for execution depending upon an expression’s truth value. Java provides two types of selection statements: if and switch. In this article we will learn about if selection statement and then next one.

In addition, in certain circumstances ?= operator can be used as an alternative to if statement. The selection statements are also called conditional statements or decision statements.

If Statement

An if statement tests a particular condition ; if the condition evaluates to true, a course of action is followed i.e., a statement or set of statements is executed. Otherwise (if the condition evaluates to false), the course of action is ignored. The syntax of the if statement is as shown below:

If (expression)
statement;

where a statement may consist of a single statement, a compound statement, or nothing (in case of empty statement). The expression must be enclosed in parentheses. If the expression evaluates to true i.e. a nonzero value, the statement is executed, otherwise ignored. Look out following code fragment:

if (ch == ‘’)
spaces++;

This statement will checks whether the character variable ch stores a space or not; if it does, the number of spaces are incremented by one. Next example will clarify some more conditions with if statement:

if (ch == ‘’)
label.setText(“It is a space character”);
if (ch >= ‘0’ && ch <= ‘9’)
label.setText(“It is a digit”);

This will compare a character variable ch. If it stores a space, it flashes a message and if it will be a digit, it flashes another message as specified in above.