In the following example, we create a string variable named txt and assign the value to "Hello world!". Then we output the value of the txt variable:
Example
<?php $txt="Hello world!"; echo $txt; ?>
Note: When you assign a text value to a variable, please remember to add single quotes to the text value or Double quotes.
Now, let’s take a look at some commonly used functions and operators for manipulating strings.
PHP Concatenation Operator
In PHP, there is only one string operator.
The concatenation operator (.) is used to concatenate two string values.
The following example demonstrates how to concatenate two string variables together:
Example
<?php $txt1="Hello world!"; $txt2="What a nice day!"; echo $txt1 . " " . $txt2; ?>
The above code will output: Hello world ! What a nice day!
Tip: In the above code, we have used the concatenation operator twice. This is due to the fact that we need to insert a space between the two strings.
PHP strlen() function
Sometimes it is useful to know the length of a string value.
strlen() function returns the length of the string (number of characters).
The following example returns the length of the string "Hello world!":
Example
<?php
echo strlen("Hello world!");
?>The above code will output: 12
Tip: strlen() is often used in loops and other functions, when it is important to determine when the string ends. (For example, in a loop, we need to end the loop after the last character in the string.)
PHP strpos() function
strpos() function is used to find a character or a specified piece of text within a string.
If a match is found in the string, this function returns the first matching character position. If no match is found, returns FALSE.
The following example finds the text "world" in the string "Hello world!":
Example
<?php
echo strpos("Hello world!","world");
?>1. A Characters, and multiple characters are strings.
2 Declaring a string must be enclosed in single quotes or double quotes.
3. Strings have no length limit and can be extended indefinitely.
4. Double quotes cannot be used within single quotes, but single quotes can also be used within double quotes.
5. Single quotes cannot be used within single quotes, and double quotes cannot be used within double quotes.
6. You can use escape characters \
The difference between single quotes and double quotes
1. Variables can be parsed in double quotes, but variables cannot be parsed in single quotes.
2 You can use escape characters in double quotes \n \r \t You cannot use escape characters in single quotes. You can only escape the single quote itself in single quotes. You can also escape the escape symbol itself
