Java If-else Statement

 

Java If Statement

Some time, in programming, we need to take some decisions or we need to handle the flow of our code according to our need. We can do this in Java with the help of If Statement. This If statement is used to handle the flow of your program execution, i.e. which statement should be executed when certain condition is fulfilled and vice versa.

The answer of the Java If Statement is in true, or false which is actually known as Boolean in Programming. If condition answer is true, we can run specific block of code and if condition answer is not true, we can run another block of code.

For Example

If we have some students of Computer Science and Information Technology and we want to assign them their Lab. So we can say that

If student belongs to Information Technology, then assign IT LAB

If student belongs to Computer Science, then assign CS LAB

Syntax of Java IF Statement

If (condition)

{

Your code to execute

}

Here, the condition answer can be either true or false. If true, then block of code in curly braces will be executed

If condition answer is not true, then the block of code in curly braces will be skipped

Example Program

Class IfTest
{
public static void main(String[] ar)
{
int age;

Age = 20;

          If(age>15)

          {

          System.out.println(“You are allowed to take admission”);

          }

}

}

Now as the number in the age variable is greater than 15, so statement inside curly braces will be executed and output will be

You are allowed to take admission

 

If else Statement in Java

As it is already discussed that Java If Statement answer can be in true or false which is also known as Boolean. So when condition answer is true, the block inside curly braces will be executed but if condition answer is not true, then nothing will be printed. So in that case, we need another block and that is known as ELSE block. This block is executed when condition answer is not true

Syntax

If (condition)
{
}
else
{

}

 

For Example

class IfElseTest
{

public static void main(String[] ar)
{

int age;

age=14;

          if(age>20)
          {

          System.out.println(“You are allowed to take admission”);
          }

          else
          {

          System.out.println(“You are not allowed to take admission”);

          }

}

 

If-else-if in Java

In Java, if-else-if is used when we have multiple conditions to check

Syntax

If (condition to check)
{
}
else if(condition to check)
{
}
else if(condition to check)
{
}
else
{

}

In the above case, if all the conditions answers are false, then else portion is executed

 

For Example

Class IfElseIfTest
{
public static void main(String[] ar)
{
          int age;
          age=20;

                   If(age>15)
                   {

                   System.out.println(“Age is greater than 15”);
                   }

                   else if(age<15)
                   {

                   System.out.println(“Age is less than 15”);
                   }

                   else

                   {

                   System.out.println(“Age is 15”);

                   }

 }

Nested If in Java

In Java, when we use if statement inside another if statement, this thing is known as Nested if

Syntax

If(condition)

{

          If()
          {

          }

          else

          {

          }

}

else

{

}

Second if is the nested if and can only be executed when the first if condition is true

 

For Example

Class NestIfTest
{

Public static void main(String[] ar)
{
String name;
int age;

name = “ali”;
age=20;

if(name==”ali)
{
          if(age==20)
          {

                             System.out.println(“Welcome”);

                             }

}

}

}

 

Output will be

Welcome

 

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