Characters other than alphabet [A-Za-z] and digits [0-9] are known as special characters like symbols & ^ % @.
Removing special characters from PHP string is very easy by using php library functions like
- preg_replace()
- str_replace()
Lets see them one by one
Using preg_replace() to remove special characters from string in PHP
PHP provides preg_replace() functions to remove special characters from string.
Lets see how to remove special characters from string in PHP using Examples.
Example: remove special characters from string in PHP.
';
$str1= preg_replace('/[^A-Za-z0-9 ]/', '', $str);
echo $str1;
?>
Output
Hello How are you $##%% friends Hello How are you friends
Here preg_replace() is used for regular expression search and replace the string.
Syntax of preg_replace is
preg_replace($pattern, $replacement, $string)
$pattern: regular expression to find in string
$replacement: $pattern will be replaced by this
$string: The string on which we will find pattern and replace it.
Example: Remove special characters from string in PHP.
';
$str1= preg_replace('/[^A-Za-z0-9 ]/', '', $str);
echo $str1;
?>
Output
Hello How are you $##%% friends Hello How are you friends
In above example
preg_replace('/[^A-Za-z0-9 ]/', '', $str);
Here $pattern is regular expression that specifies.
Consider A-Z and a-Z and 0-9 characters and a space (” “) in $str string.
Other then this replace any character with ”.
Example: Remove special characters except ! and . from string in PHP.
';
$str1= preg_replace('/[^A-Za-z0-9!. ]/', '', $str);
echo $str1;
?>
Output
Hello! How are you $##%% friends. Hello! How are you friends.
In above example two special characters are part of string ! and . we dont want to remove these two special characters for that we have included these two characters in pattern.
Using str_replace to remove special characters from PHP String
Syntax of str_replace is
str_replace($search, $replace, $string);
str_replace($search, $replace, $string, $count)
$search: The character or string you want to search on $string
$replace: $search will be replaced with $replace
$string: on given string we will apply search and replace
$count: Keep record of how many replacement performed.
Example: PHP program to remove special characters from string except dot
";
$spchar = array("!", "@", "#", "$", "%", "^", "&", "*", "(", ")", ",", "/", "{", "}", "[", "]");
$str1 = str_replace($spchar, "", $str);
echo $str1;
?>
Output
Hello! How are you $##%% friends. Hello How are you friends.
In above example we have created a character array of special characters and we want to replace with “”.
Result of str_replace() is stored in $str1.
Removing html elements from PHP string
";
$str1 = preg_replace("/&#?[a-z0-9]{2,8};/i","",$str);
echo $str1;
?>
Output
Hello &bsp; > < How are you friends. Hello How are you friends.
In above example there are three html elements values showing as a part of string &bsp; > <
To remove this we used preg_replace("/&#?[a-z0-9]{2,8};/i","",$str);
This regular expression is taken from StackOverFlow
Removing comma and currency symbol from PHP String
Removing comma from currency
";
$str1 = str_replace(",", "", $str);
echo $str1;
?>
Output
INR 20,400 INR 20400
Removing comma (,) and currency symbol from PHP string currency
";
$replace=array(",","INR");
$str1 = str_replace($replace, "", $str);
echo $str1;
?>
Output
INR 20,400 20400
Using preg_replace() to remove currency symbol.
";
$str1 = preg_replace('/[^0-9]/s', "", $str);
echo $str1;
?>
Output
$ 20,400 20400
If you want to remove only currency symbol and dont want to remove comma (,) then you can use following regular expression with preg_replace().
preg_replace('/[^0-9,]/s', "", $str);