This example covers two programs to count the number of digits in an integer.

- the first program uses the iterative function,
- The second program uses the Recursive function.

Consequently, Both are uses to implement digit count for a given number.

you should be familiar with the following Go language features for this program.

- Golang For Loop control structure
- Golang For Loop Range form
- Golang read input from user
- Golang Recursion Function Guide

The below code write to read an integer value from a user keyboard and find the number of digits.

For example, if a user inputs 245 as a number, the result of this program is 3.

## How to get the count digit count of an integer using an iterative function?

Here is a step-by-step.

- The program reads an integer from the user console and stores it in a variable number.
- The For Loop is used to iterate through all the digits until the condition (number!= 0) is false, i.e. number=0.

For Input number=456, the `Iteration`

function executes the sequence of steps.

- Once the First Iteration of for loop is complete, the number will be 45 and the count is incremented by 1, count=1.
- After the second iteration is completed, the number will be 4, and the count is incremented by 1 ie count=2.
- After the third iteration is completed, a number will be 0, and the count is incremented by 1 ie count=3.
- For loop condition expression is evaluated to false(number=0), For loop is terminated.
- the count is returned to the main function

Finally, a count is printed to console using the `Println`

function in the main function.

```
package main
import "fmt"
func iterativeDigitsCount(number int) int {
count: = 0
for number != 0 {
number /= 10
count += 1
}
return count
}
func main() {
number: = 0
fmt.Print("Please enter number: ")
fmt.Scanln( & number)
fmt.Printf("Digits count of %d is %d", number, iterativeDigitsCount(number))
}
```

When you run the above program, Output is

```
Please enter number: 456
Digits count of 456 is 3
Please enter number: 2
Digits count of 2 is 1
```

## Example program - count number of digits of an integer using the Recursive function

A `recursive`

function is a function which calls inside the same function.

Here is a recursive Function execution flow for given input number=2546.

```
recursionCountDigits(2546)
\-- 1+ recursionCountDigits(254)
-- 2+ recursionCountDigits(25)
-- 3+ recursionCountDigits(2)
-- 3+ 1 returns 4 to main function
```

Following is an **example for a Recursive function to count the number of digits of a number**

```
package main
import "fmt"
func main() {
number: = 0
fmt.Print("Please enter number: ")
fmt.Scanln( & number)
fmt.Printf("Digits count of %d is %d", number, recursionCountDigits(number))
}
func recursionCountDigits(number int) int {
if number < 10 {
return 1
} else {
return 1 + recursionCountDigits(number / 10)
}
}
```

Output is

```
Please enter number: 2546
Digits count of 2546 is 4
Please enter number: 456789
Digits count of 456789 is 6
```

## Conclusion

Learn how to calculate digit count in a given integer number in the golang program using iterative and recursive functions.