php: parse string to get string

Question

How would I extract the number 33 before the underscore in the following?

33_restoffilename.txt.

would something like following work?

int strPos = strpos("33_filename.txt", "_");
str num = substr ("33_filename.txt" , 0 , strPos );

Answer 1

If the naming convention is always number_filename.ext , you can use explode() :

//Put the filename into the variable $name
$name = "33_restoffilename.txt";

//Split the name by "_"
$parts = explode("_", $name);

//Get the first part of the name from the array (position 1)
$number = $parts[0];

//Output
echo $number;

This will output

33

Answer 2

there are may way to achive this:

Method 1:

$strPos = strpos("33_filename.txt", "_");
echo $num = substr("33_filename.txt" , 0 , $strPos );

Method 2:

$str = '33_filename.txt';
$str_arr = explode('_', $str);
echo $num = $str_arr[0];

Answer 3

Use strstr() .

$str = '33_filename.txt';
$num = strstr($str, '_', true);

Answer 4

Method - 1

$getIntegerFromBeginning = substr($string, 0, strspn($string, "0123456789"));
echo $getIntegerFromBeginning;

Method - 2

$getIntegerFromBeginning = explode("_", $string, 2);
echo  $getIntegerFromBeginning[0];

Replace $string with exact string.

Answer 5

Use this

$string = '33_filename.txt';

$arrString = explode('_', $string);

echo $value = $arrString[0]; //Will output 33

Answer 6

This is really very simple we don't need these string functions in this case. Just do type casting and you will get integer number. It will be fast and easy

$pp='33_restoffilename.txt';
echo (int)$pp;

No need to make it complicated