# PHP | octdec( ) Function

In the earlier days of computing, octal numbers and the octal numbering system was very popular for counting inputs and outputs because as it works in counts of eight, inputs and outputs were in counts of eight, a byte at a time. Due to a wide usage of octal number system many times it happens that we require converting an octal number to its decimal equivalent. There are many methods to convert an octal number to its decimal equivalent but they are a bit time-consuming. But PHP provides us with an in-built function which can be used to convert an octal number to its decimal equivalent.

The octdec() function is a built in function in PHP and is used to calculate the decimal equivalent of an octal number. The octdec() function converts numbers that are too large to fit into the integer type, larger values are returned as a float in that case.

Syntax:

`octdec(value)`

Parameters: This function accepts a single parameter \$value . It is a string which represents the octal number whose decimal equivalent you want to find.

Return Value:It returns the decimal representation of octal number passed as a string to the function.

Examples:

```Input : octdec("46")
Output : 38

Input : octdec("3098")
Output : 24

Input : octdec("-105")
Output : 69
```

Below program illustrate the working of octdec() in PHP:

1. When a positive number is passed as a parameter:

 ` `

Output:

`24`
2. When a negative number is passed as a parameter:

 ` `

Output:

`69`

Important points to note:

• It converts an octal number to its decimal equivalent.
• It returns the values as float if the numbers are too large to be returned as integer type .
• Octal number system is not as popular as hexadecimal number system these days.
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