## Introduction:

The `int`

class in `Dart`

contains two properties to check if a number is *even* or *odd*. We can use these properties to find out quickly if a number is *odd* or *even*. In this tutorial, I will show you how to do that with an example:

### Method 1: By using the `isEven`

and `isOdd`

properties:

A number is called an *even* number if it is perfectly divisible by *2*. Else, it is called an *odd* number. The `isEven`

and `isOdd`

are two boolean properties defined in the `int`

class. These properties of an integer can be used to check if a number is even or odd. The value of `isEven`

is `true`

for an even number. Else, it will be `false`

. Similarly, the value of `isOdd`

is `true`

if it is an odd number, and it will be `false`

otherwise.

#### Example program:

In the below example, we are taking one *number* as input from the user and it prints if the number is *odd* or *even*. It uses the `isEven`

and `isOdd`

properties to check if the number is *even* or *odd*.

```
import 'dart:io';
void main() {
int? number;
print("Enter a number : ");
var data = stdin.readLineSync();
number = int.tryParse(data ?? '-1');
if (number == null) {
print("Invalid input.");
} else if (number.isEven) {
print("$number is an even number");
} else if (number.isOdd) {
print("$number is an odd number");
}
}
```

Download it on GitHub

#### Sample Output:

If you run the above program, it will give outputs as below:

```
Enter a number :
12
12 is an even number
Enter a number :
13
13 is an odd number
```

Note that it will also work for negative numbers. For example, *-12* will be considered an *even* number.

### Method 2: By using the modulo operator:

Another traditional way is to use the *modulo operator*, `%`

to check if a number is *even* or *odd*. The modulo operator returns the remainder of a division operation. For an even number `n`

, the value `n%2`

is *0*. Similarly, for an odd number `n`

, the value of `n%2`

is *1*.

The following program shows how to use the modulo operator to check if a number is even or odd:

```
import 'dart:io';
void main() {
int? number;
print("Enter a number : ");
var data = stdin.readLineSync();
number = int.tryParse(data ?? '-1');
if (number == null) {
print("Invalid input.");
} else if (number % 2 == 0) {
print("$number is an even number");
} else if (number % 2 == 1) {
print("$number is an odd number");
}
}
```

Download it on GitHub

If you run the above program, it will print the same output.

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