PHP programming language (1) - operators

1. Assignment operator

“=” Used to assign values to variables   

" x+ = y"==="x=x+y"

" x- = y"==="x=x-y"

" x * =y"==="x*y"

" x/ =y"===="x=x/y"

" x% =y"==="x=x%y"

" x. =y"==="x=x.y"

2. Arithmetic operator

“+”    and

 “-”    Bad

 “*”  ride

 “/”    except （php Different from other languages , This has decimals ） 

“%”  x%y model ,x Divide y The remainder of

“-x”  -x Take the opposite

“.”    x.y    Juxtaposition , Connect two strings

php7+ Version added intdiv（）, The return value of this function is the value of the first parameter divided by the second parameter and rounded

3.PHP Increasing / Decrement operator

++x      Want to increase ,x+1, Then return x

x++      After increasing , return x, then x+1

--x      Want to decrease ,x-1, Then return x

x--      Post decline , return x, then x-1

4.PHP Comparison operator （ The return values are Boolean ）

x==y be equal to , Only compare values , Do not compare types

x===y Absolutely equal to , Compare values , Also compare types

x!=y It's not equal to

x<>y It's not equal to

x!==y Absolutely not equal to , The type cannot be the same

x>y Greater than

x<y Less than

x>=y Greater than or equal to

x<=y Less than or equal to

5.php Logical operators

x and y And If x and y All for true, Then return to true

x or y or If x and y At least one is true, Then return to true

x xor y Exclusive or If x and y There is and only one for true, Then return to true

x&&y And If x and y All for true, Then return to true

x||y or If x and y At least one is true, Then return to true

!x Not If x Not for true, Then return to true

5.PHP Array operators

x+y aggregate x and y Set

x==y equal If x and y With the same key / It's worth it , Then return to true

x===y Identity If x and y With the same key / It's worth it , And the order is the same, the type is the same , Then return to true

x!=y It's not equal to

x<>y It's not equal to

x!==y Absolutely not equal to , The type cannot be the same

6. Ternary operator

Format ：a ？ b：c

intend ：a When established , The return value is b, If not, the return value is c

a？？a:b

When it means ：a Return... When not present b, Return when there is c

7. Combination comparator （php7 Above version ）

Grammar format ：

$c=$a<=>$b;

If $a>$b, be $c=1

If $a==$b, be $c=0

If $a<$b, be $c=-1