Java if else
if Statement
Use the if statement to specify a block of Java code to be executed if a condition is true.
if (condition) {
  // block of code to be executed if the condition is true
}Sample program with if
 Write a program or WAP to find a number is greater or not.
class SampleIf
{
   public static void main(String args[])
   {
      int a=10;
      if (a > 0) {
         System.out.println("a is greater than 0");
      } 
   }
}Output:
if-else Statement
Use the if statement to specify a block of Java code to be executed if a condition is true.
if (condition) {
  // block of code to be executed if the condition is true
}
else{
  // block of code to be executed if the condition is false
}Sample program with if-else
 Write a program or WAP to find which number is greater.
class SampleIfElse
{
   public static void main(String args[])
   {
      int a=10;
      if (a > 0) {
         System.out.println("a is greater than 0");
      }
      else
      {
         System.out.println("a is smaller than 0");
      }  
   }
}
 
Output:
Ladder if-else Statement
If we have multiple conditions for a program then we need to use ladder if – else.
if (condition) {
  // block of code to be executed if the condition is true
}
else if (condition) {
  // block of code to be executed if the condition is true
}
else {
  // block of code to be executed if the condition is true
}
Sample program with Ladder if-else
 Write a program or WAP to find a number is positive (+ve), negative (-ve) or zero (0).
class SampleLadderIfElse
{
   public static void main(String args[])
   {
      int a=10;
      if (a > 0) {
         System.out.println("a is +ve");
      }
      else if (a < 0) {
         System.out.println("a is -ve");
      }
      else {
         System.out.println("a is zero");
      }
   }
}Output:
Nested if else Statement
If we use the if - else statement within another if - else then we use nested if - else .
if (condition) {
  if (condition) 
  {
      // block of code to be executed if the condition is true
  }
  else
  {
     // block of code to be executed if the condition is false
  }
}
else
{
   if (condition) {
      // block of code to be executed if the condition is true
   }
   else
   {
     // block of code to be executed if the condition is false
   }
}
Sample program with Nested if-else
 Write a program or WAP to find which number is greatest in three given number.
class SampleNestedIfElse
{
   public static void main(String args[])
   {
      int a=10,b=20,c=30;
      if (a>b)
      {
         if (a>c)
         {
             System.out.println("a is greatest.");
         }
         else
         {
              System.out.println("c is greatest.");
         }
     }
     else
     {
        if (b>c) 
        {
             System.out.println("b is greatest.");
        }
        else
        {
             System.out.println("c is greatest.");
        }
     } 
   }
}