C # Getting Started note 3 expressions and operators

C # expressions

expressions, which combine variables, literals, and operators to create expressions, are the basic components of a calculation.
Literal: Is the number, string, or value typed in the source code that represents the specified type. There are several commonly used: integers, real numbers, characters, strings .

Full digital polygon "can also use hexadecimal table":

• • 123//Plastic
  • 123L//Long Plastic
  • 123U//unsigned shaping
  • 123UL//unsigned long shaping

Real Digital Polygon Amount:

• • 1.5F//float Type
  • 1.5//double Type
  • 1.5M//decimal Type

Character literal:

• • ' A '//char type
  • ' \ n '//simple escape sequence: Backslash + single character
  • ' \x0061 '//16 binary escape sequence
  • ' \u005a '//unicode escape sequence

string literal:

• "Hi There";
• "Val\t5,val\t10";
• @ "C:\Program Files\Microsoft";

Note: The string is prefixed with @, and all content in double quotes, including content that is normally considered an escape sequence, is strictly printed as listed in the string.

operator, broadly divided into 3 classes.

• Unary operator, which handles one operand
• Binary operator, handling two operands "most"
• Ternary operator, handling three operands

numeric operators

Operator	Category	An example expression	Results
+	Two Yuan	Var1=var2+var3	The value of var1 is the sum of var2 and VAR3
-	Two Yuan	Var1=var2-var3	The value of var1 is the difference between var2 and VAR3.
*	Two Yuan	Var1=var2*var3	The value of VAR1 is the product of VAR2 and VAR3
/	Two Yuan	Var1=var2/var3	The value of VAR1 is var2 divided by the value of VAR3.
%	Two Yuan	Var1=var2%var3	The value of var1 is the remainder of var2 divided by var3
+	One dollar	Var1=+var2	The value of var1 equals the value of VAR2
-	One dollar	Var1=-var2	The value of var1 equals the value of var2 multiplied by-1

String operators

Operator	Type	An example expression	Results
+	Two Yuan	Var1=var2+var3	The value of VAR1 is two string concatenated values stored in VAR2 and VAR3

Increment and decrement operators

• + + Always use operands plus 1
• --Always use operands minus 1

Operator	Type	An example expression	Results
++	One dollar	VAR1=++VAR2;	The value of var1 is var2+1,var2 increment by 1
--	One dollar	VAR1=--VAR2;	The value of var1 is var2-1,var2 decrement by 1
++	One dollar	var1=var2++;	The value of var1 is var2,var2 increment by 1
--	One dollar	var1=var2--;	The value of var1 is var2,var2 decrement by 1

Assignment operators

Operator	Type	An example expression	Results
=	Two Yuan	VAR1=VAR2;	Var1 is given the value of VAR2
+=	Two Yuan	VAR1+=VAR2;	Var1 is endowed with var1 and VAR2 and
-=	Two Yuan	VAR1-=VAR2;	Var1 was given the difference between var1 and var2.
*=	Two Yuan	VAR1*=VAR2;	VAR1 is given the product of VAR1 and VAR2
/=	Two Yuan	VAR1/=VAR2;	Var1 is given the result of dividing var1 and var2
%=	Two Yuan	VAR1%=VAR2;	Var1 is given the remainder obtained by dividing the var1 from the VAR2

Operator Precedence

Priority level	Operator
Excellent First Level By High To Low	++,--(used as a prefix); +,-(unary)
	*，/，%
	+,-
	=,*=,/=,%=,+=,-=
	++,--(used as a suffix)

Note: parentheses can be used to override the order of precedence.

C # Getting Started note 3 expressions and operators