PHP String Functions
A String is a collection of characters. A string variable can contain alphabets, digits, and special characters. In PHP, we can perform some operation on string using built in PHP string functions.
Example 1: String Length
$a = "PHP is a scripting language"; $len = strlen($a); echo "String Length is $len";
Example 2: String word count
$a = "PHP is a scripting language"; $count = str_word_count($a); echo "Total words are $count";
Example 3: String Reverse
$a = "PHP is a scripting language"; $rev = strrev($a); echo "String Reverse = $rev";
Example 4.1: Find string position
$a = "PHP is a scripting language"; $pos = strpos($a, "scripting"); echo "Position of scripting in string is $pos";
Example 4.2: Find string position with proper message.
$a = "PHP is a scripting language";
$search = "is";
$pos = strpos($a, $search);
if($pos===false)
echo "Not found";
else
if($pos>=0)
echo "String found at $pos position";
Example 5: Strchr() function
$a = "PHP is a client side scripting language"; $search = "scripting "; echo strchr($a, $search);
Example 6: Replace all found string.
$a = "PHP is a client side scripting language";
//str_replace("word to be find", "new word to be replace with", "string");
echo str_replace("PHP", "JavaScript", $a);
Example 7: Compare 2 strings
$str1="new delhi";
$str2="new york";
//$str3=strcmp($str1,$str2);
//$str3=strcasecmp($str1,$str2); //ignore cases
$str3 = strncmp($str1,$str2,4);
if($str3==0){
echo "Both strings are equal";
}
else
if($str3>0){
echo "1st strings is greater";
}
else{
echo "2nd strings is greater";
}
Example 8: Convert string into lowercase.
$a = "PHP is a client side scripting language"; $b = strtolower($a); $c = strtoupper($a); echo "<br>String in Lowercase: ".$b; echo "<br>String in Uppercase: ".$c;
Example 9: Converts the first character of a string in uppercase.
$a = "PHP is a client side scripting language"; echo "<br>ucfirst: ".ucfirst($a); echo "<br>ucwords: ".ucwords($a);
Example 10: Shuffles all characters in a string randomly.
$a = str_shuffle("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()");
echo "<br>After Shuffle String is: ".$a;
Example 11: substr() function
$a = "PHP is a client side scripting language";
//substr("string", "starting value", "length");
echo substr($a, 9, 6);//returns client
Example 12: str_repeat() function
echo str_repeat("-",80);// display '-' hyphen 80 times
Example 13: trim() function
$a = " PHP String "; echo "<br>". $a; echo "<br>". trim($a);
Example 14: wordwrap() function
$a = "PHP is a client side scripting language"; echo "<br>".wordwrap($a, 5, "<br>");
Example 15: explode() function
$a = "PHP is a client side scripting language";
//explode(separator,string);
$b = explode(" ",$a)
echo "<br>First word is: ".$a;
Example 16: htmlentities() function
$a = "<br> is use for break line"; echo htmlentities($a);//convert < with <
Exercise 1: CREATE a login form & check for username and password. is valid or not.(strcmp) also check the password length (strlen) should be in between 8-32. username is not case sensitive. (strcasecmp/strtolower). Assume username = admin/ADMIN/Admin and password = admin123
