php study notes page 2/2

Basic PHP syntax and data types:
(1) Basic PHP syntax:
1. Htm and php mix
2. A statement ends with ; (semi-colon)
3. How to define a variable and use it
(2) PHP data operation type
Four scalar types:
boolean (boolean type) is understood as true or false
integer (integer)
float (float, also called "double")
Understand as a decimal
string (string)
Two composite types:
array (array)
object(object)
boolean (boolean type) is understood as true or false

$bo=TRUE; $bo=FALSE;

integer (integer)

$bo=1; $bo=-12;

float (float, also called "double") is understood as a decimal type

$bo=1.001; $bo=3.1415926;
string (string)

$bo="This string or EN Word";

array (array)

$bo=array(1,2,3,4); $bo=array(“A”=>1 , “B”=>2);
Here is my first php program source code:

Introduction and application of commonly used PHP operations types
1. Arithmetic operations
example:

5 * 6 - 12
2*(28+1)

Note: Arithmetic operations follow mathematical operations rules

From left to right, first calculate multiplication and division and then add or subtract. When encountering brackets, first calculate inside brackets.
2. Assignment operation
example:

$a=1;
$a+=2;
$a*=3;

Note: Assign the value to the left variable.
3. Comparative operations
example:

1==2
3!=2
5<3
"ok"=="ok"
1==='1'

Note: The value obtained by the comparison operation is a Boolean value
4. Logical operations
example:

1 && 1
0 && 1
1 || 1
1 || 0

5. Increase and decrease operations
example:

$a++
++$a
$a--
--$a


php source code:

Operator: