Today, you will learn about **conditional logic** in Java and how to use `if` statements.

# `if` statement

Below, is the syntax for an if-then statement in Java:

```
if (condition) {
    commands
}
```

The condition will either return `true` or `false`. If the condition is `true`, the commands within the `if` statement will execute. If the condition is `false`, the statements will not execute and the program will move on to the next lines of code.

**Example**

class main {
    public static void main( String args[] ) {
        int num = 15;

        if(num < 10){
            System.out.println("num is less than 10");
        }

        if(num > 10){
            System.out.println("num is greater than 10");
        }
    }
}

In the example above, we have an integer variable called `num` with a value of $15$. The first `if` statement checks if `num` is less than $10$. Since $15$ is not less than $10$, the command within the first `if` statement will not execute. 

The next `if` statement checks whether `num` is greater than $10$. Because $15$ is greater than $10$, the print statement nested below will be executed.

# `if`... `else` statement

```
if (condition) {
    commands
} else {
    commands
}
```

Looking at the syntax above, the `if` statement will check a condition. If the condition is `true`, the commands nested under the `if` statement will be executed. Then, it will skip past the `else` statement. 

However, if the condition in the `if` statement is `false`, the commands under the `else` statement will be executed.

**Example**

class main {
    public static void main( String args[] ) {
        int num = 15;

        if (num < 10) {
            System.out.println("num is less than 10");
        } else {
            System.out.println("num is greater than 10");
        }
    }
}

In the example above, we once again have an integer variable called `num`. The `if` statement checks whether `num` is less than $10$. Because `num` has a value of $15$, the print statement nested below the `if` statement will not execute. 

Because the condition in the `if` statement returned `false`, the command under the `else` statement will run and print out, `num is greater than 10`.

If you are looking for a simplified way to write an `if`... `else` statement, consider reading about [ternary operators in Java](https://www.educative.io/answers/ternary-operator-in-java).

# `if`... `else if`... `else` statement

```
if (condition) {
    commands
} else if (condition) {
    commands
} else (condition) {
    commands
}
```

When working with `if`... `else if`... `else` statements, the first `if` statement will check a condition. If the condition is `true`, the commands nested below it will run and then skip past the `else if` and `else` statements.

However, if the `if` condition is `false`, the program will move onto the  `else if` statement and evaluate its condition. If the condition is `true`, the commands nested below it will execute and the program will skip past the `else` statement. If the condition is `false`, the commands nested under the `else` statement will execute.

class main {
    public static void main( String args[] ) {
        int num = 20;

        if (num < 10) {
            System.out.println("num is less than 10");
        } else if (num > 10 && num <= 15) {
            System.out.println("num is greater than 10 and less than 15");
        } else {
            System.out.println("num is greater than 15");
        }
    }
}

It's also possible to have multiple `else if` statements if you would like to handle more cases.

If you're interested in learning about other conditional statements, check out our Edpresso shot about the [switch statement in Java](https://www.educative.io/answers/how-to-use-the-switch-statement-in-javascript).

How to use if statements in Java

if statements in Java execute commands based on conditions, using syntax patterns: if, if-else, and if-else if-else.

How to use if statements in Java

`if` statement

`if`… `else` statement

`if`… `else if`… `else` statement

How to use if statements in Java

if statement

if… else statement

if… else if… else statement

`if` statement

`if`… `else` statement

`if`… `else if`… `else` statement