# Arrow Function in Dart

### Arrow Function In Dart

Dart has a special syntax for the function body, which is only one line. The arrow function is represented by **=>** symbol. It is a shorthand syntax for any function that has only one expression.

### Syntax

The syntax for the dart arrow function.

```
returnType functionName(parameters...) => expression;
```

Info

**Note**: The arrow function is used to make your code short.**=> expr** syntax is a shorthand for **{ return expr; }**.

### Example 1: Simple Interest Without Arrow Function

This program finds simple interest without using the arrow function.

```
// function that calculate interest
double calculateInterest(double principal, double rate, double time) {
double interest = principal * rate * time / 100;
return interest;
}
void main() {
double principal = 5000;
double time = 3;
double rate = 3;
double result = calculateInterest(principal, rate, time);
print("The simple interest is $result.");
}
```

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### Example 2: Simple Interest With Arrow Function

This program finds simple interest using the arrow function.

```
// arrow function that calculate interest
double calculateInterest(double principal, double rate, double time) =>
principal * rate * time / 100;
void main() {
double principal = 5000;
double time = 3;
double rate = 3;
double result = calculateInterest(principal, rate, time);
print("The simple interest is $result.");
}
```

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### Example 3: Simple Calculation Using Arrow Function

This program finds the sum, difference, multiplication, and division of two numbers using the arrow function.

```
int add(int n1, int n2) => n1 + n2;
int sub(int n1, int n2) => n1 - n2;
int mul(int n1, int n2) => n1 * n2;
double div(int n1, int n2) => n1 / n2;
void main() {
int num1 = 100;
int num2 = 30;
print("The sum is ${add(num1, num2)}");
print("The diff is ${sub(num1, num2)}");
print("The mul is ${mul(num1, num2)}");
print("The div is ${div(num1, num2)}");
}
```

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### Video

Watch our video on arrow functions in Dart.