Go while Loop

In Go, we use the while loop to execute a block of code until a certain condition is met.

Unlike other programming languages, Go doesn't have a dedicated keyword for a while loop. However, we can use the for loop to perform the functionality of a while loop.

Syntax of Go while loop

 for condition { // code block }

Here, the loop evaluates the condition. If the condition is:

• true - statements inside the loop are executed and condition is evaluated again
• false - the loop terminates

Flowchart of while loop in Go

Example: Go while loop

 // Program to print numbers between 1 and 5 package main import ("fmt") func main() { number := 1 for number <= 5 { fmt.Println(number) number++ } }

Output

 1 2 3 4 5

Here, we have initialized the number to 1.

1. During the first iteration, the condition number <= 5 is true. Hence, 1 is printed on the screen. Now, the value of number is increased to 2.
2. Again the test condition, number <= 5 is true. Hence, 2 is also printed on the screen and the value of number is increased to 3.
3. This process continues until number becomes 6. Then, the condition number <= 5 will be false and the loop terminates.

Create multiplication table using while loop

 // Program to create a multiplication table of 5 using while loop package main import ("fmt") func main() { multiplier := 1 // run while loop for 10 times for multiplier <= 10 { // find the product product := 5 * multiplier // print the multiplication table in format 5 * 1 = 5 fmt.Printf("5 * %d = %d\n", multiplier, product) multiplier++ } }

Output

 5 * 1 = 5 5 * 2 = 10 5 * 3 = 15 5 * 4 = 20 5 * 5 = 25 5 * 6 = 30 5 * 7 = 35 5 * 8 = 40 5 * 9 = 45 5 * 10 = 50

Here, we have initialized the multiplier := 1. In each iteration, the value of the multiplier gets incremented by 1 until multiplier <= 10.

Go do...while Loop

In Go, we can use the same for loop to provide the functionality of a do while loop. For example,

 // Program to print number from 1 to 5 package main import "fmt" func main(){ number := 1 // loop that runs infinitely for { // condition to terminate the loop if number > 5 { break; } fmt.Printf("%d\n", number); number ++ } }

Output

 1 2 3 4 5

Notice the if statement inside the for loop.

 if number > 5 { break; }

This statement acts as the while clause inside a do...while loop and is used to terminate the loop.