PHP mobile Internet Development notes (3) -- Operators

PHP mobile Internet Development notes (3) -- Operators

 

 

 

I. PHP Operators

 

PHP has a rich set of operators, most of which are directly from the C language. Operators can be divided into Arithmetic Operators, string operators, value assignment operators, bitwise operators, conditional operators, and logical operators. When operators are in the same expression, their operations have a certain priority.

(1) arithmetic operations

+-*/% + + --

(2) string Operators

The character string operator has only one. (point), which is an English ending. It can connect a string to form a new string, or connect a string to a number. The type is automatically converted.

 

View source print? 1. $a = dawanganban ; 2. $b = 123 ; 3. echo $a . $b ; // Output result: dawanganban123(3) value assignment operator

 

 

View source print? 01. = += -= *= /= %= .= 02. 03. 04. 05. $a = dawanganban ; 06. $a .=1; 07. $a .=2; 08. $a .=3; 09. echo $a . $b ; // Output result: dawanganban123(4) bitwise operators & | ~ ^ <>

(5) Comparison Operators

 

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

<>: Not equal to or! = Same

===: Constant, equal value and consistent type

! ==: Non-constant, with inconsistent values or types

 

1. View source print?1.echo 5 == 5; // True PHP is a weak language (variables in js are similar) 2.echo 5 === 5; // False is completely equal(6) logical operations

    

   AND (logical AND) OR (logical OR) XOR (logical OR) & (logical AND) | (logical OR )! (Non-logical)

    

   View source print?1.var_dump(5 && ); //false 2.var_dump(5 && 2); //true 3.var_dump(5 || ); //true 4.var_dump(0 xor 1); //true 5.var_dump(0 xor 0); //false 6.var_dump(1 xor 1); //false