Creating Strings:

• Strings can be created using single quotes (') or double quotes (").

$string1 = 'Single quoted string';
$string2 = "Double quoted string";

Concatenation:

• Strings can be concatenated using the dot (.) operator or the compound assignment operator (.= ).

$concatenated = $string1 . ' ' . $string2;
$concatenated .= ' Appended text';

String Length:

• Use the strlen() function to get the length of a string.

$length = strlen($string1);

Substring:

• Extract parts of a string using substr() function.

$substring = substr($string1, 0, 6); // Extracts first 6 characters

String Replacement:

• Replace occurrences of a substring using str_replace() function.

$newString = str_replace('old', 'new', $string1);

String Case:

• Convert string case using strtolower(), strtoupper(), ucfirst(), ucwords() functions.

$lowercase = strtolower($string1);
$uppercase = strtoupper($string1);
$capitalizeFirst = ucfirst($string1);
$capitalizeWords = ucwords($string1);

String Trimming:

• Remove whitespace or specific characters from the beginning and end of a string using trim(), ltrim(), rtrim() functions.

$trimmed = trim($string1);

String Splitting:

• Split a string into an array using explode() function based on a delimiter.

$parts = explode(' ', $string1); // Split by space

String Joining:

• Join array elements into a string using implode() or join() function.

$joined = implode(', ', $parts); // Join with comma and space

String Comparison:

• Compare two strings using strcmp(), strcasecmp(), or equality operators (==, ===).

$result = strcmp($string1, $string2);
if ($string1 === $string2) {
    // Strings are equal
}

Regular Expressions:

• Use regular expressions for advanced string manipulation and pattern matching using functions like preg_match(), preg_replace(), etc.