NBKRIST JavaHub – Java Conditions

Java Conditional Expressions – Easy Guide

Conditions help Java programs make decisions. These allow Java to choose different execution paths depending on values or states at runtime.

1. Introduction

Java decision-making statements allow programs to behave differently under different conditions. They control program flow based on boolean expressions (true/false).

The main conditional expressions are: if, nested if, if–else, and the ternary operator.

2. The if Expression

if checks a condition, and if it's true, executes a block of statements.

int marks = 85;
if(marks > 50){
    System.out.println("Pass");
}

Pass

3. Nested if Expressions

You can put one if inside another. Useful for multi-level decisions.

int marks = 90;
if(marks > 50){
    if(marks > 80){
        System.out.println("Distinction");
    }
}

Distinction

4. if–else Expression

When condition is true → execute block A, else → execute block B.

int age = 16;
if(age >= 18){
    System.out.println("Eligible to Vote");
}else{
    System.out.println("Not Eligible");
}

Not Eligible

5. Ternary Operator (?:)

Ternary is a compact form of if–else. Syntax: condition ? value1 : value2.

int num = 7;
String res = (num % 2 == 0) ? "Even" : "Odd";
System.out.println(res);

Odd

6. The switch Statement

The switch statement allows multi-way branching based on the value of an expression. It is clearer than writing multiple if–else-if chains.

It compares a value against multiple case labels and executes the matching block.

int day = 3;
switch(day){
    case 1: System.out.println("Monday"); break;
    case 2: System.out.println("Tuesday"); break;
    case 3: System.out.println("Wednesday"); break;
    default: System.out.println("Invalid Day");
}

Wednesday

Practice Questions – Click to Reveal Answers

1️⃣ What is the purpose of an if statement?

To execute code only when a condition is true.

2️⃣ What is a nested if?

An if statement written inside another if statement.

3️⃣ Write syntax of if–else.

if(condition){ }
else { }

4️⃣ What does the ternary operator return?

One of two values based on the condition.

5️⃣ What is the output of: (5 > 3 ? "Yes" : "No")?

Yes

Quick Summary

If statements check conditions.
Nested if allows multi-level checking.
If–else handles two-way decisions.
Ternary is a short version of if–else.
These concepts are the foundation of decision-making in Java.