Data Type is PHP
Integer
Double
Boolean TRUE / FALSE case insensitive
String (There is no character type in PHP)
String can be defined using single quotes or double quotes
In single quoted string newline character or escape sequences or embedded variables are not recognized. But using double quoted strings escape sequence and embedded variable are recognized.
For example
‘Result is: $sum’ displayed as it is
“Result is: $sum” displayed with $sum value
Boolean TRUE / FALSE case insensitive
If the expression is in integer context then it evaluates to false if result of the expression is zero else it is true
If the string expression is used in Boolean context then it evaluates to false if the result of the expression is empty string or “0” otherwise its true even “0.0” is true
if it’s a double expression then 0.0 evaluates to false otherwise its true