Go for Loop#

In programming, a loop is used to repeat a block of code. For example,

If we want to print a statement 100 times, instead of writing the same print statement 100 times, we can use a loop to execute the same code 100 times.

This is just a simple example; we use for loops to clean and simplify complex programs.

#Golang for loop

In Golang, we use the for loop to repeat a block of code until the specified condition is met.

Here's the syntax of the for loop in Golang.

for initialization; condition; update {
  statement(s)
}

Here,

1. The initialization initializes and/or declares variables and is executed only once.
2. Then, the condition is evaluated. If the condition is true, the body of the for loop is executed.
3. The update updates the value of initialization.
4. The condition is evaluated again. The process continues until the condition is false.
5. If the condition is false, the for loop ends.

#Working of for loop

#Example 1: Golang for loop

// Program to print the first 5 natural numbers

package main
import "fmt"

func main() {

  // for loop terminates when i becomes 6
  for i := 1; i <= 5; i++ {
    fmt.Println(i)
  }

}

Output

1
2
3
4
5

Here is how this program works.

#Example 2: Golang for loop

// Program to print numbers for natural numbers 1 + 2 + 3 + ... +n

package main
import "fmt"

func main() {
  var n, sum = 10, 0

  for i := 1 ; i <= n; i++ {
    sum += i    // sum = sum + i
  }

  fmt.Println("sum =", sum)
}

Output

sum = 55

Here, we have used a for loop to iterate from i equal to 1 to 10.

In each iteration of the loop, we have added the value of i to the sum variable.