PHP Topics / Tutorial - String Datatype, Data types in php

Topic

How to define a string variable and assign value?

Explanation

A string is a sequence of characters. A string can be delimited by single quotes or double quotes. The declaration of a string variable is same as that of other variable. The only difference is that the value that you want to store in a string variable must be enclosed in inverted commas or quotes.

For Example:

$str1 = "This is a string datatype variable";
$str2 = 'This is also a string datatype variable';

String declared within double-quotes are subject to variable substitution and escape sequence handling, while string declared within single-quotes will not perform variable subsitution and escape sequence handling.

For example:

$str="Integer";
echo "String\t$str\n";

RESULT:
String Integer

This displays "String" followed by a space and then "Integer" followed by a newline. Here variable substitution is performed on the variable $str and the escape sequences are converted to their corresponding characters.

echo 'String\t$str\n';

RESULT:
String\t$str\n

In this case, the output is exactly "String\t$str\n". There is no variable substitution or handling of escape sequences, the string within the inverted commas are printed as such.

String Concatenation is a process of adding two strings. This is done by attaching one string to the end of another string. This is done by using '.' (period) operator as shown below

$str1="Hello";
$str2="World";
echo "$str1"."$str2";

RESULT:
HelloWorld

This displays value of $str1 as "Hello" followed by value of $str2 as "World".

String datatype in PHP