Original PHP Tutorial: Operators

Original PHP Tutorial: Operators

I. arithmetic operators

+-*/% + + --

II. string operators.

III. assignment operators

= + =-= * =/= % =. =

IV. Comparison operators

><>====! = Or <>! =

5. logical operators

& Or and | or! Or not

VI. bitwise operators

& | ^ ~ <>>>>> // Converts all data to binary for calculation.

7. Other operators

? : ''@ =>->::& $

Details

------------------------------------------------------------------------

%

Convert the numbers on both sides into integers before performing operations.

Do not use decimal divisor. do not use a negative number if it cannot be 0.

There are two purposes: Division operation; control range

A. division operation

$ Year = 2010; // calculates whether $ year is a leap year.

If ($ year % 4 = 0 & $ year % 100! = 0) | $ yaer % 400 = 0)

{

Echo & quot; 11111111111111 & quot ";

}

Else

{

Echo & quot; 0000000000000 & quot ";

}

B. Control scope

$ Num = 10900009; // control $ num not greater than 10

Echo $ num % 10;

------------------------------------------------------------------------

Connection operator number

$ Name = "tom ";

$ Age = 27;

$ Height = 1.75;

Echo "My name is: {$ name} my age is: {$ age} my height is: {$ height} meters
";

Echo 'My name is: '. $ name.' My age is: '. $ age.' My height is: '. $ height. 'MI '.'
';

Echo "\ $ age =". $ age;

------------------------------------------------------------------------

& Or and | or! Or not

$ Username = "admin ";

$ Password = "123456 ";

$ Email = "";

If ($ username = "admin" & $ password = "123456 ")

{

Echo "the user name and password are entered correctly
";

}

If ($ username = "" | $ password = "" | $ email = "")

{

Echo "all values cannot be blank
";

}

If (isset ($ email )&&! Empty ($ email) | (isset ($ phone )&&! Empty ($ phone )))

{

Echo "there is a contact method ";

}

------------------------------------------------------------------------

^

Bitwise operators are different or only two data types are true.

------------------------------------------------------------------------

~

Bitwise operators convert 0 and 1 (unary operators)

------------------------------------------------------------------------

</>

The bitwise operator shifts left/right to delete the part that is removed from the left to add 0 to the part that is removed from the left to the right.

The right shift is equivalent to/2, and the left shift is equivalent to * 2.

------------------------------------------------------------------------

>>>

Bitwise operator shifts right unsigned

0 is added for all blank areas

------------------------------------------------------------------------

Special note

Short circuit problem: & and | short circuit may occur // Use & and | during calculation, both sides will calculate this problem.

& When performing an operation, if the previous number is false, whether the subsequent value is true or not, and the entire expression is false, the subsequent operands are not executed.

| During the operation, if the previous number is true, whether or not it is followed by false, and the entire expression is true,

Example:

$ Num = 10;

If ($ num> 5 | $ num ++ <100)

{

}

Echo $ num;

 

Result: 10

------------------------------------------------------------------------

''

The execution operator uses the content in the back quotes as instructions for execution.

$ Str = 'ipconfig/all ';

Echo'

';
echo $str;
echo '

';

------------------------------------------------------------------------

@

Shield warnings and errors

@ GetType ();

Echo "##############
";

------------------------------------------------------------------------

Use () operator priority