Go has only `for` loop. The basic `for` loop has three components separated by `;` -
* the **init** statement: executed before the first iteration
* the **condition** expression: evaluated before every iteration
* the **post** statement: executed at the end of every iteration
The **init** statement is often a short variable declaration. The variables declared there are visible only in the scope of the `for` statement. The loop stops iterating once the boolean condition evaluates to false.
An example of the `for` loop is given below -
**for.go**
```go
package main
import "fmt"
func main() {
sum := 0
for i := 0; i <= 10; i++ {
sum += i
}
fmt.Println("The sum of first 10 natural numbers is", sum)
}
```
Running the above program produces an output similar to the following output -
```
$ go run for.go
The sum of first 10 natural numbers is 55
```
You can use `continue` and `break` to adjust the loops flow
```go
// this code prints any odd numbers up to 5
for n := 0; n <= 10; n++ {
if n % 2 == 0 {
// if the number is even jump to the next n
continue
}
fmt.Println(n)
// if the number is 5 exit the loop
if n == 5 {
break
}
}
```
If you want to create an infinite loop just use `for { }`
```go
for {
// Whill loop until a condition breaks the loop
break // exit the loop
}
```
## Replacement for while-loop
To simulate while-loop of other languages, you can simply exclude the **init** and **post** statement:
```go
func main() {
num := 1
for num <= 1000 {
num *= 2
}
fmt.Println("The smallest power of 2 above 1000 is", num)
The do-while-loop is useful as the statement is executed at least once before the condition is checked and continue until the condition is no longer true. To simulate the do-while-loop of other languages we can use an infinite for loop with a break condition at the end. The traditional do-while has the following syntax.
```
do {
statement
} while (condition);
```
We can simulate this syntax in go as follows:
```
for {
statement
if (!condition) { break }
}
```
A Go example
```go
x := 0
for {
// These statements are ran at least once
x++
fmt.Println(x)
// Check do the condition at the end. If it is no longer true end the loop
