PHP String Functions

In PHP, strings are sequences of characters, such as letters, numbers, and symbols, enclosed within single quotes (”) or double quotes (“”). PHP provides a variety of string functions to manipulate and work with strings effectively. Here’s an overview of PHP strings and some commonly used string functions:

1. Declaring Strings:

$var1 = 123;
$string1 = 'Single quoted string $var1';
echo $string1; // output: Single quoted string $var1
$string2 = "Double quoted string $var1";
echo $string2 // output: Double quoted string 123

2. Concatenation:

Concatenation is the process of combining two or more strings into one.

$name = "John";
$greeting = "Hello, " . $name . "!"; // Output: Hello, John!

3. String Length:

Returns the length of a string.

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

4. Substring:

Returns a part of a string.

$string = "Hello, World!";
$substring = substr($string, 7); // Output: World!

5. String Replace:

Replaces all occurrences of a search string with a replacement string.

$string = "Hello, World!";
$newString = str_replace("World", "PHP", $string); // Output: Hello, PHP!

6. String to Lowercase/ Uppercase:

Converts a string to lowercase/uppercase.

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

7. Trimming:

Removes whitespace or other predefined characters from the beginning and end of a string.

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

8. String Splitting:

Splits a string into an array of substrings based on a delimiter.

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

9. String Comparison:

Compares two strings. Returns 0 if the strings are equal, a negative value if the first string is less than the second, and a positive value if the first string is greater than the second.

$string1 = "apple";
$string2 = "banana";
$result = strcmp($string1, $string2); // Output: A negative value

10. String Searching:

Searches for a substring within a string. Returns the position of the first occurrence if found, or false otherwise.

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

11. String Formatting:

Formats a string using placeholders.

• $name = "John";
$age = 30;
$message = sprintf("My name is %s and I am %d years old.", $name, $age); // Output: My name is John and I am 30 years old.

These are just a few examples of the many string functions available in PHP. String manipulation is a common task in PHP programming, and mastering these functions will enable you to work with strings effectively and efficiently in your applications.