 # Kotlin Program to Convert Octal Number to Decimal and vice-versa

In this program, you'll learn to convert octal number to a decimal number and vice-versa using functions in Kotlin.

## Example 1: Program to Convert Decimal to Octal

``````fun main(args: Array<String>) {
val decimal = 78
val octal = convertDecimalToOctal(decimal)
println("\$decimal in decimal = \$octal in octal")
}

fun convertDecimalToOctal(decimal: Int): Int {
var decimal = decimal
var octalNumber = 0
var i = 1

while (decimal != 0) {
octalNumber += decimal % 8 * i
decimal /= 8
i *= 10
}

return octalNumber
}``````

When you run the program, the output will be:

`78 in decimal = 116 in octal`

This conversion takes place as:

```8 | 78
8 | 9 -- 6
8 | 1 -- 1
8 | 0 -- 1
(116)
```

## Example 2: Program to Convert Octal to Decimal

``````fun main(args: Array<String>) {
val octal = 116
val decimal = convertOctalToDecimal(octal)
println("\$octal in octal = \$decimal in decimal")
}

fun convertOctalToDecimal(octal: Int): Int {
var octal = octal
var decimalNumber = 0
var i = 0

while (octal != 0) {
decimalNumber += (octal % 10 * Math.pow(8.0, i.toDouble())).toInt()
++i
octal /= 10
}

return decimalNumber
}``````

When you run the program, the output will be:

`116 in octal = 78 in decimal`

This conversion takes place as:

`1 * 82 + 1 * 81 + 6 * 80 = 78`

Here's the equivalent Java code: Java program to convert octal to decimal and vice-versa