PHP String Manipulation: Common string functions (strlen, strpos, str_replace, etc.).

Here's a quick rundown of some common string manipulation functions in PHP, which are essential for handling text and data processing.

1. strlen() - Get the Length of a String

The strlen() function returns the length of a string.

$string = "Hello, World!";
echo strlen($string); // Output: 13

2. strpos() - Find Position of First Occurrence of a Substring

The strpos() function finds the position of the first occurrence of a substring within a string. It returns false if the substring is not found.

$string = "Hello, World!";
$position = strpos($string, "World");
echo $position; // Output: 7

3. str_replace() - Replace All Occurrences of a Search String with a Replacement

The str_replace() function replaces all occurrences of a specified string with another string.

$text = "Hello, World!";
$replacedText = str_replace("World", "PHP", $text);
echo $replacedText; // Output: "Hello, PHP!"

4. substr() - Extract a Portion of a String

The substr() function extracts a portion of a string. You can specify the start position and optionally the length.

$string = "Hello, World!";
$subString = substr($string, 7, 5); // Start at position 7, get 5 characters
echo $subString; // Output: "World"

5. strtoupper() and strtolower() - Convert String to Uppercase or Lowercase

The strtoupper() function converts a string to uppercase, while strtolower() converts it to lowercase.

$string = "Hello, World!";
echo strtoupper($string); // Output: "HELLO, WORLD!"
echo strtolower($string); // Output: "hello, world!"

6. ucfirst() and ucwords() - Capitalize First Letter(s)

ucfirst() capitalizes the first letter of a string.
ucwords() capitalizes the first letter of each word in a string.

$text = "hello, world!";
echo ucfirst($text); // Output: "Hello, world!"
echo ucwords($text); // Output: "Hello, World!"

7. trim() - Remove Whitespace from Both Sides of a String

The trim() function removes whitespace (or other specified characters) from the beginning and end of a string.

$string = "   Hello, World!   ";
echo trim($string); // Output: "Hello, World!"

8. strrev() - Reverse a String

The strrev() function reverses the characters in a string.

$string = "Hello, World!";
echo strrev($string); // Output: "!dlroW ,olleH"

9. strcmp() - Compare Two Strings

The strcmp() function compares two strings. It returns 0 if both strings are equal, a negative number if the first string is less than the second, and a positive number if the first string is greater.

$string1 = "Hello";
$string2 = "World";
echo strcmp($string1, $string2); // Output: negative number (since "Hello" < "World")

10. explode() - Split a String by a Delimiter

The explode() function splits a string into an array based on a specified delimiter.

$string = "apple,banana,orange";
$array = explode(",", $string);
print_r($array); // Output: Array ( [0] => apple [1] => banana [2] => orange )

11. implode() - Join Array Elements into a String

The implode() function joins array elements into a single string with a specified delimiter.

$array = ["apple", "banana", "orange"];
$string = implode(", ", $array);
echo $string; // Output: "apple, banana, orange"

These functions cover a range of basic string operations commonly used in PHP development.

PHP Arrays: Types of arrays (indexed, associative, multidimensional), array functions.

PHP Date and Time: Date and time handling with DateTime class