Introduction to PHP string variables

String variables are used for values that contain characters.

After creating the string, we can operate on it. You can use the string directly in the function or store it in a variable.

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

Note: When you assign a text value to a variable, please remember to add single quotes or double quotes to the text value.

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

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

The above code will output: 12

Prompt: strlen () is often used in loops and other functions when it is important to determine when a 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 within a string A character or a specified length of text.

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

The above code will output: 6

Tip: In the above example, the position of the string "world" is 6. The reason it's 6 instead of 7 is that the first character in the string is at position 0, not 1.

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