[Note] C # basic introduction -- Arithmetic Operators of C,
Add: +.The plus sign has two purposes: When the plus sign is used to connect two numbers, the sum of the two numbers is calculated. For example:
Console. WriteLine (9 + 2.2); // output 11.2
In another case, when both sides of the plus sign contain strings, the expressions on both sides are connected to new strings. For example:
Console. WriteLine (9 + "2.2"); // output 92.2
Because "2.2" is a string, 9 is also converted to "9", and + serves as the connection string.
Minus :-.Subtraction is used for subtraction. For example:
Console. WriteLine (15-23); // output-8
Multiplication :*.Multiplication is used to obtain the product of the number 2. For example:
Console. WriteLine (0.8*3); // output 2.4
Except :/. Division number is used to calculate the operator of division of two numbers. For example:
Console. WriteLine (2/0. 5); // output 4.0
However, if two integers are separated, only the integer part is retained and the fractional part is removed.
Console. WriteLine (5/10); // output 0
Remainder Operator-- The remainder operator in C # Is%.
The Division operator is used to calculate the operator for division of two numbers, while the remainder operator % is used to calculate the remainder of division of two numbers. For example:
Console. writeLine (19/5); // calculates the 19 operator divided by 5 and outputs 3 console. writeLine (19% 5); // calculate the remainder of 19 divided by 5, and output 4 (more than 3 4)
In programming, % is often used to check whether a number can be divisible by another number. For example, the following code snippet:
Int number = 29; Console. WriteLine (number % 2); // calculates the remainder of number divided by 2
If the output is 0, there is no remainder, that is, the number can be divisible by 2 (an even number); If the output is 1, there is a remainder, that is, the number cannot be divisible by 2 (an odd number ).
Operator ++ and --
++, CalledAuto-increment operator. For example, if you are 18 years old and you are one year old next year, write the code as follows:
Int age = 18; // 18 years old this year age = age + 1; // next year, add 1 year old to this year's age
You can also write it as follows:
Int age = 18; // age + + 18 this year; // next year, add 1 year to this year's age
Age ++; the same role as age = age + 1 is that of variable + 1.
--, CalledAuto-subtraction Operator. Similarly, if you are 18 years old, you will be 17 years old next year after using XX Xiaoshui. You can write as follows:
Int age = 18; // age 18 this year --; // equivalent to age = age-1;
In addition, age ++; and age --; can also write ++ age; or -- age;
However, pleaseNote:If ++ is written before or after a variable in the same statement as other operations, see the following example:
Console. WriteLine (age ++); is equivalent to the following two sentences:
Console. WriteLine (age); // print age = age + 1 first; // then add
Console. WriteLine (++ age); is equivalent to the following two sentences:
Age = age + 1; // first add Console. WriteLine (age); // then print
The output results will not be the same if the operation order is different.
The above is taken from MOOC course C # getting started with development