PHP study notes (2) data types

";/* C style */"; # C++ single line comment style?>11" "Single quotesSingle quotes will be treated as ordinary strings Output$i='hello,world!';echo "$i";?>$i(boolean)141516171819Return TRUE on success, or FALSE on failure$foo = "5bar"; // string$bar = true; // booleansettype($bar, "string"); // $bar is now "1" (string)

Serial number	Symbol	Name	Function	Remarks
1	echo	Output character	Same as python’s print statement will be immediately followed by The string or variable value after is displayed on the page
2	;	semicolon	is used after the code to indicate the end
3	?>	XML Markup style	is used to include code to distinguish it from html code Recommended, the server cannot be disabled	echo "hello, world!"; ?>
4	< ;script language="php">	script style
5	?>	Short style	Short style and ASP style need to be set in php.ini, set both short_open_tag and asp_tags to ON	echo 'hello, world!'; ?>
6	%>	ASP style	Short style and ASP style need to be set in php.ini, set both short_open_tag and asp_tags for ON	echo 'hello, world!'; %>
7	//	comment symbol	C++ style	echo "	" echo "
Multi-line comments	?>		9	# comment symbol shell style echo "
	10	$	variable identifier	All variables must be preceded by the '$' symbol
' '		Double quotes	Variables contained in double quotes will be automatically replaced with actual values
echo " "; echo '$i';	Display results hello ,world!		12 definator 13
convert to Boolean	(boolean)$num, (boolean) $str
(string)	converted into character type	(string)$boo, (string)$flo
(integer)	converted into integer type	( integer)$boo, (integer)$str
(float)	convert to floating point type	(float)$str
(array)	convert to array	(array)$str
(object)	Convert to object	(object)$str
settype()	type conversion function	settype(needs to be converted Variable, converted type)
settype($foo , "integer"); // $foo is now 5 (integer)	?>		The above introduces PHP study notes (2) data types, including PHP learning and data types. I hope it will be helpful to friends who are interested in PHP tutorials.