Precedence of Operators

Write code often do not know which operator priority is higher, I add a parenthesis, long time to think this way is not good, so still carefully summed up, strive to do a rigorous program.

The following are from high to low:

Priority Level	type of Operation	Relevance of	operator
19	圆括号	N/A	( … )
18	成员访问	From left to right	… . …
	需计算的成员访问	From left to right	… [ … ]
	new(with parameter list)	N/A	new … ( … )
17	Function call	From left to right	… ( … )
	New (no parameter list)	From right to left	new …
16	Post increment (operator behind)	N/A	… ++
	Post decrement (operator behind)	N/A	… --
15	Logical Non-	From right to left	! …
	Bitwise non-	From right to left	~ …
	One-dollar addition	From right to left	+ …
	One-dollar subtraction	From right to left	- …
	Forward increment	From right to left	++ …
	Forward Decrement	From right to left	-- …
	typeof	From right to left	typeof …
	void	From right to left	void …
	Delete	From right to left	delete …
14	Multiplication	From left to right	… * …
	Division	From left to right	… / …
	Take the mold	From left to right	… % …
13	Addition	From left to right	… + …
	Subtraction	From left to right	… - …
12	Bitwise LEFT Shift	From left to right	… << …
	Bitwise RIGHT SHIFT	From left to right	… >> …
	Unsigned Right Shift	From left to right	… >>> …
11	Less than	From left to right	… < …
	Less than or equal	From left to right	… <= …
	Greater than	From left to right	… > …
	Greater than or equal	From left to right	… >= …
	Inch	From left to right	… in …
	instanceof	From left to right	… instanceof …
10	Equals	From left to right	… == …
	Non-equal sign	From left to right	… != …
	Full equals	From left to right	… === …
	Non-full equals	From left to right	… !== …
9	Bitwise-AND	From left to right	… & …
8	Bitwise XOR OR	From left to right	… ^ …
7	Bitwise OR	From left to right	… | …
6	Logic and	From left to right	… && …
5	Logical OR	From left to right	… || …
4	Conditional operators	From right to left	… ? … : …
3	Assign value	From right to left	… = …
			… += …
			… -= …
			… *= …
			… /= …
			… %= …
			… <<= …
			… >>= …
			… >>>= …
			… &= …
			… ^= …
			… |= …
2	Yield	From right to left	yield …
	yield*	From right to left	Yield* ...
1	Spread	N/A	......
0	Comma	From left to right	… , …

Here are a few chestnuts:

New Foo.getname ();  According to the 18th one inside is actually new (Foo.getname ())

New Foo (). GetName ();
According to the 18th one is actually (new Foo ()). GetName () The member access is the highest priority here, so first the. GetName is executed.

However, when the left-hand value is taken, new Foo () can be understood as two operations: New with parameters (that is, new Foo ()) and function calls (that is, Foo () before the value is new).

The new parameter has a higher precedence than the function call, so the new Foo () is executed first, or the instance object of the Foo class is given, and then the member is accessed. GetName.

New New Foo (). GetName ();//According to the 18th one is actually new ((New Foo ()). GetName ())

　　

Precedence of Operators