A string is a sequence of characters, like “Hello world!”.
Strings
Strings in PHP are surrounded by either double quotation marks, or single quotation marks.
Example
echo "Hello";
echo 'Hello';
Note There is a big difference between double quotes and single quotes in PHP.
Double quotes process special characters, single quotes does not.
Double or Single Quotes?
You can use double or single quotes, but you should be aware of the differences between the two.
Double quoted strings perform action on special characters.
E.g. when there is a variable in the string, it returns the value of the variable:
Example
Double quoted string literals perform operations for special characters:
$x = "John";
echo "Hello $x";
Single quoted strings does not perform such actions, it returns the string like it was written, with the variable name:
Example
Single quoted string literals returns the string as it is:
$x = "John";
echo 'Hello $x';
String Length
The PHP strlen() function returns the length of a string.
Example
Return the length of the string “Hello world!”:
echo strlen("Hello world!");
Word Count
The PHP str_word_count() function counts the number of words in a string.
Example
Count the number of word in the string “Hello world!”:
echo str_word_count("Hello world!");
Search For Text Within a String
The PHP strpos() function searches for a specific text within a string.
If a match is found, the function returns the character position of the first match. If no match is found, it will return FALSE.
Example
Search for the text “world” in the string “Hello world!”:
echo strpos("Hello world!", "world");
Tip: The first character position in a string is 0 (not 1).
Complete PHP String Reference
For a complete reference of all string functions, go to our complete PHP String Reference.
The PHP string reference contains description and example of use, for each function!