operator in Java/Python/Go/Javascript

2015-02-0122

Operator	Java	Go	Python	Javascript
++, –	statement	not statement, expression	N/A	supported
logical	&,\|,&&,\|\|,!	&&,\|\|,!	and, or, not	&&,\|\|,!
bitwise not	~x	^x	~x	~x
bitwise and	x & y	x & y	x & y	x & y
bitwise or	x \| y	x \| y	x \| y	x \| y
bitwise exclusive or	x ^ y	x ^ y	x ^ y	x ^ y
bitwise clear (and not)	N/A	&^	N/A	N/A
?: (ternary op)	supported	N/A	N/A	supported

Java: &, | also have the logical function. But it differents with &&, || which have short circuiting function.
javascript special operator
- instanceof: Test object class
- in: Test whether property exists, prop in objectName
  - in object: test property whether in object
  - ** in array**: test index (not element) whether in array
    1
    2
    3
    4
    5
    var testInArray = [7, 8, 9];
    "0" in testInArray; // true
    1 in testInArray; // true
    "7" in testInArray; // false
    8 in testInArray; // false
- delete: Remove a property
- typeof: Determine type of operand
- void: return undefined value
- >>>: Shift right with zero extension
- ===, !== : Test for strict equality/inequality, type and value should be tested.
- !!x: get equality of boolean of x
go
- ++, –: only supports post increment/decrement

/*** java ***/
Int demoInt2 = demoInt1++
++demoInt1
- x ==y, x != y // value equals or not
- x.equals(y) // same object

### python ###
>>>a**b == pow(a, b)
>>>(a//b, a%b) == (a//b, a%b) == divmod(a, b)
>>> x == y, x !=y  # value equals or not, check __eq__
>>> x is y, x is not y  # same object or not, check pointer
x in y, x not in y
>>> abs(-5) == 5
True
>>> a = 2
>>> ~a
>>> from struct import pack
>>> pack('b', -1)
'\xff'
# build-in function for sequence, dict
min(), max(), sum(), cmp()

/*** go ***/
demoInt2 := demoInt1++ // syntax error
++demoInt1 //syntax error
x := 2
x, ^x   // 0010 -> 1101 -> (1101 -1) -> 1100 -> 1011

本文作者：Kasper Deng
本文链接：http://kasperdeng.github.io/2015/02/01/OperatorInJavaPythonGoJS/
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