An if/else statement is critical to decision-making in programs and is one of the most valuable tools in Java programming. With an if/else statement, you can specify which block of code to execute based on the outcome of a condition. If the condition is false, the code in the else branch will execute.

Relational Operators:

Relational operators can be used to specify a condition in an if statement.

• Less than: a < b

• Less than or equal to: a <= b

• Greater than: a > b

• Greater than or equal to: a >= b

• Equal to: a == b

• Not equal to: a != b

if Statement

• The if statement allows you to specify a block of code to execute if its condition is true. If the condition is false, its block of code will not execute.

else if Statement

• The else if statement is used to specify an additional condition to test if the condition for the if statement evaluates to false. If the condition for the else if statement is true, its block of code will execute. If it is false, its block of code will not execute.

else Statement

• The else statement allows you to specify a block of code to execute if the condition for the if statement evaluates to false.

One-Way Selection Statement

if (17 > 12) {
   System.out.println("The condition evaluated to true.");
}

Two-Way Selection Statement

if (17 < 12) {
   System.out.println("The condition evaluated to true.");
}
else {
   System.out.println("In the else block");
}

Multi-Selection Statements

if (17 < 12) {
   System.out.println("Less Than.");
}
else if (17 == 17) {
   System.out.println("Equal To.");
}
else {
   System.out.println("Greater Than.");
}

You can also use nested if statements to evaluate multiple conditions that must be true before a block of code is executed. For example:

if (17 >= 17) {
   if (17 == 17) {    
      System.out.println("EQUAL");
   }
}