Conditional operators in Java

1) Simple if / else

Check equality and output the result.

// example: simple if/else
int a = 1;
if (a == 1) {
    System.out.println("Условие выполняется: a == 1");
} else {
    System.out.println("Условие не выполняется");
}
    

Output when a = 1: Condition is met: a == 1

2) else if — chain of checks

When you need to check several options one after another.

int a = 2;
if (a == 1) {
    System.out.println("a == 1");
} else if (a == 2) {
    System.out.println("a == 2");
} else {
    System.out.println("none of the options");
}
    

Tip: the order is important — the first matching if/else if "absorbs" the execution.

3) Comparison Operators and Negation

• != — not equal
• >, < — greater / less
• >=, <= — greater/less or equal
• ! — logical "not" for boolean expressions

int a = 3;
if (a != 2) {
    System.out.println("a не равно 2");
}
if (a > 2) {
    System.out.println("a больше 2");
}
    

4) Logical operators: && (AND) and || (OR)

Composite conditions.

int a = 3, b = 1;
// logical AND: both conditions must be true
if (a == 3 && b == 1) {
    System.out.println("both conditions are true");
}
// logical OR: it’s enough for at least one to be true
if (a == 2 || b == 1) {
    System.out.println("at least one is true");
}
    

5) Ternary Operator — Compact, but Cautious

Shortened form of if/else. Good for simple assignments, but beginners are better off reading the regular if.

int a = 3, b = 1;
int c = (b == 1) ? (a + 1) : (a - 1);
System.out.println(c);
    

If b == 1, then c = a + 1, otherwise c = a - 1.

6) switch — when there are many discrete options

Easy to read, especially with many integer/string cases. Don't forget break.

int a = 5;
switch (a) {
    case 1:
        System.out.println("a == 1");
        break;
    case 2:
        System.out.println("a == 2");
        break;
    case 3:
        System.out.println("a == 3");
        break;
    default:
        System.out.println("Condition not met");
}
    

7) A small cheat sheet for debugging

• To understand why it doesn't enter the condition — print the values of the variables before checking.
• Check types: comparison == for references (objects) — is not the same as for primitives.
• The ternary operator is good in one line — but do not make complex logic in it.