# Go For Loops

The `for` loop loops through a block of code a specified number of times.

The `for` loop is the only loop available in Go.

## Go for Loop

Loops are handy if you want to run the same code over and over again, each time with a different value.

Each execution of a loop is called an iteration.

The `for` loop can take up to three statements:

### Syntax

for statement1; statement2; statement3 {
// code to be executed for each iteration
}

statement1 Initializes the loop counter value.

statement2 Evaluated for each loop iteration. If it evaluates to TRUE, the loop continues. If it evaluates to FALSE, the loop ends.

statement3 Increases the loop counter value.

Note: These statements don't need to be present as loops arguments. However, they need to be present in the code in some form.

## for Loop Examples

### Example 1

This example will print the numbers from 0 to 4:

package main
import ("fmt")

func main() {
for i:=0; i < 5; i++ {
fmt.Println(i)
}
}

Result:

``` 0 1 2 3 4 ```
Try it Yourself »

#### Example 1 explained

• i:=0; - Initialize the loop counter (i), and set the start value to 0
• i < 5; - Continue the loop as long as i is less than 5
• i++ - Increase the loop counter value by 1 for each iteration

### Example 2

This example counts to 100 by tens:

package main
import ("fmt")

func main() {
for i:=0; i <= 100; i+=10 {
fmt.Println(i)
}
}

Result:

``` 0 10 20 30 40 50 60 70 80 90 100 ```
Try it Yourself »

#### Example 2 explained

• i:=0; - Initialize the loop counter (i), and set the start value to 0
• i <= 100; - Continue the loop as long as i is less than or equal to 100
• i+=10 - Increase the loop counter value by 10 for each iteration

## The continue Statement

The `continue` statement is used to skip one or more iterations in the loop. It then continues with the next iteration in the loop.

### Example

This example skips the value of 3:

package main
import ("fmt")

func main() {
for i:=0; i < 5; i++ {
if i == 3 {
continue
}
fmt.Println(i)
}
}

Result:

``` 0 1 2 4 ```
Try it Yourself »

## The break Statement

The `break` statement is used to break/terminate the loop execution.

### Example

This example breaks out of the loop when i is equal to 3:

package main
import ("fmt")

func main() {
for i:=0; i < 5; i++ {
if i == 3 {
break
}
fmt.Println(i)
}
}

Result:

``` 0 1 2 ```
Try it Yourself »

Note: `continue` and `break` are usually used with conditions.

## Nested Loops

It is possible to place a loop inside another loop.

Here, the "inner loop" will be executed one time for each iteration of the "outer loop":

### Example

package main
import ("fmt")

func main() {
adj := [2]string{"big", "tasty"}
fruits := [3]string{"apple", "orange", "banana"}
for i:=0; i < len(adj); i++ {
for j:=0; j < len(fruits); j++ {
}
}
}

Result:

``` big apple big orange big banana tasty apple tasty orange tasty banana ```
Try it Yourself »

## The Range Keyword

The `range` keyword is used to more easily iterate through the elements of an array, slice or map. It returns both the index and the value.

The `range` keyword is used like this:

### Syntax

for index, value := range array|slice|map {
// code to be executed for each iteration
}

### Example

This example uses `range` to iterate over an array and print both the indexes and the values at each (`idx` stores the index, `val` stores the value):

package main
import ("fmt")

func main() {
fruits := [3]string{"apple", "orange", "banana"}
for idx, val := range fruits {
fmt.Printf("%v\t%v\n", idx, val)
}
}

Result:

``` 0      apple 1      orange 2      banana ```
Try it Yourself »

Tip: To only show the value or the index, you can omit the other output using an underscore (`_`).

### Example

Here, we want to omit the indexes (`idx` stores the index, `val` stores the value):

package main
import ("fmt")

func main() {
fruits := [3]string{"apple", "orange", "banana"}
for _, val := range fruits {
fmt.Printf("%v\n", val)
}
}

Result:

``` apple orange banana ```
Try it Yourself »

### Example

Here, we want to omit the values (`idx` stores the index, `val` stores the value):

package main
import ("fmt")

func main() {
fruits := [3]string{"apple", "orange", "banana"}

for idx, _ := range fruits {
fmt.Printf("%v\n", idx)
}
}

Result:

``` 0 1 2 ```
Try it Yourself »

## Exercise:

Print i as long as i is less than 6.

```package main
import ("fmt")
func main() {
i:=0; i < 6;  {
fmt.Println(i)
}
}
```

Start the Exercise

×

## Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail:
sales@w3schools.com