Php Boolean type (Boolean)

This is the simplest type. Boolean represents the TRUE value, which can be TRUE or FALSE. This is the simplest type. Boolean represents the TRUE value, which can be TRUE or FALSE.

Syntax

To specify a Boolean value, use the keyword TRUE or FALSE. Both are case insensitive.

 Generally, the result of the boolean value returned by the operator is passed to the control flow.
 

Convert to a Boolean value

To convert a value to a boolean value explicitly, use (bool) or (boolean) to forcibly convert the value. However, in many cases, forced conversion is not required, because this value is automatically converted when the operator, function, or flow control structure requires a boolean parameter.

See identify type conversion.

When converted to boolean, the following values are considered FALSE:

Boolean value FALSE

Integer value 0 (0)

Floating point value: 0.0 (0)

Empty string and string "0"

Array that does not contain any elements

Objects that do not include any member variables (applicable only to PHP 4.0)

Special type NULL (including unassigned variables)

SimpleXML object generated from an XML document without any tags

All other values are considered to be TRUE (including any resources ).

Warning

-1 is considered TRUE like other non-zero values (both positive and negative values!