String datatype in PHP
How to define a string variable and assign value?
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.
$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.
$str="Integer"; Result :
This displays "String" followed by a space and then "Integer" followed by a newline. Here variable substitution is performed on the variable $str and the escape sequences are converted to their corresponding characters.
echo 'Stringt$strn';Result :
In this case, the output is exactly "Stringt$strn". 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"; Result :
This displays value of $str1 as "Hello" followed by value of $str2 as "World".