HTML tutorial
CSS3 tutorial
Bootstrap tutorial
JavaScript tutorial
JQuery tutorial
AngularJS tutorial
React tutorial
NodeJS tutorial
PHP tutorial
Python tutorial
Python3 tutorial
Django tutorial
Linux tutorial
Docker tutorial
Ruby tutorial
Java tutorial
C tutorial
C ++ tutorial
Perl tutorial
JSP tutorial
Lua tutorial
Scala tutorial
Go tutorial
ASP.NET tutorial
C # tutorial
The for loop loops through a block of code a specified number of times.The for loop is the only loop available in Go
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:
for statement1; statement2; statement3 {
// code to be executed for each iteration
}
Note: These statements don't need to be present as loops arguments. However, they need to be present in the code in some form.
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
Example 1 explained
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
Example 2 explained
The continue statement is used to skip one
or more iterations in the loop. It then continues with the next iteration in the loop.
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
The break statement is used to break/terminate the loop execution.
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
Note: continue and break are usually used with conditions.
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":
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++ {
fmt.Println(adj[i],fruits[j])
}
}
}
Result:
big apple
big orange
big banana
tasty apple
tasty orange
tasty banana
The range keyword is used to more easily iterate
over an array, slice or map. It returns both the index and the value.
The range keyword is used like this:
for index, value := array|slice|map {
// code to be executed for each iteration
}
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
_).
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
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