# GO Program to Calculate Sum of Natural Numbers Using for.....Loop

In this example, using simple for........ loop to calculate the sum of natural numbers(the positive numbers 1, 2, 3... are known as natural numbers) from 1 to n (entered by the user).

### Example

```
``````
// Sum of n natural number (the positive numbers 1, 2, 3... are known as natural numbers)
package main
import "fmt"
func main(){
var n,sum int
fmt.Print("Enter a positive integer : ")
fmt.Scan(&n)
for i:=1; i<=n; i++ { // assigning 1 to i
sum += i // sum = sum + i
}
fmt.Print("Sum : ",sum)
}
```

**The Go for loop has three forms, only one of which has semicolons.**

for init; condition; post { } Like a C for

for condition { } Like a while

for { } Endless loop