Arithmetic operations in C++

C is a high-level programming language widely used in the field of computer science and plays a very important role in computer programming. Among them, arithmetic operations are one of the most basic and common operations in C programming. This article will further explore arithmetic operations in C.

1. Variables and Constants

In C, a variable refers to a memory address that is assigned a specific value in the program. A constant refers to a value that cannot be changed in the program. It is recommended that when writing a program, you add a prefix to the variable name, such as i, j, k, etc., which represent integer type variables, f, d, etc., which represent floating point type variables, and c, which represents a character type variable. It can improve code readability and maintainability to a certain extent.

Declaring a variable or constant requires first clarifying its data type. This data type determines the data type that the variable/constant can store and the amount of space it occupies. In C, common data types include integer, floating point, character, Boolean, etc. The specific type and the amount of space it occupies may vary between compilers and operating systems.

2. Arithmetic operators

Commonly used arithmetic operators in C include addition, subtraction, multiplication, division, modulus, etc. Its meaning is as follows:

a.: Addition operation, adding two numbers. For example, a b is the result of adding variable a and variable b.

b. -: Subtraction operation, subtract two numbers. For example, a-b is the result of subtracting variable a and variable b.

c. : Multiplication operation, multiply two numbers. For example, ab is the result of multiplying variable a and variable b.

d. /: Division operation, divide one number by another number. For example, a/b is the result of dividing variable a by variable b.

e. %: Modulo or remainder operation, calculates the value of the remainder after dividing two numbers, that is, a%b is the remainder of a divided by b.

Use arithmetic operators and assignment operators in combination to achieve a simple compound assignment method. For example: a =b means that the result of adding a and b is first assigned to a, and the abbreviation is a=a b . In the same way, a-=b, a*=b, a/=b, a%=b and so on.

3. Increment and decrement operators

In loops, we often need to add 1 or subtract 1 to the value of a variable. C provides the increment operator ( ) and decrement operator (--) to accomplish this task. The increment operator will increase the value of the variable by 1, and the decrement operator will decrease the value of the variable by 1. Depending on the position of the operator, its application is also different:

a. Prefix operator: a or --a means to add 1 or subtract 1 from a first, and then use the value of a.

b. Postfix operator: a or a-- means first using the value of a, and then adding or subtracting 1 to a.

Note: In an operation, only one of the increment or decrement operators can be used. At the same time, you should pay attention to the precedence of operators to avoid unnecessary errors.

4. Type conversion of arithmetic operations

In C, sometimes there will be operations between different data types, and the compiler will automatically perform type conversion. Type conversion is mainly divided into implicit type conversion and explicit type conversion:

a. Implicit type conversion: refers to the compiler automatically converting one data type into another data type. For example, when an integer is operated on a floating-point number, the integer is converted into a floating-point number. Implicit type conversion does not require special syntactic marking.

b. Explicit type conversion: also called forced type conversion, refers to forcing one data type to another data type. For example, to convert floating-point data to integer data, you need to use the cast operator, that is, put the variable and type name together and enclose them in parentheses, such as (int)f.

It should be noted that when performing type conversion, the following rules should be followed:

a. Smaller types can be automatically converted to larger types, but larger types cannot be converted For smaller types.

b. If an operator requires two operands, and their data types are different, then the operator type is selected according to the following rules: First, if one of the operands is of type double , the other operand will be converted to type double; otherwise, if the type of one of the operands is float, the other operand will be converted to type float; otherwise, if the type of one of the operands is long double, then the other operand will be converted to type long double; otherwise, if one of the operands is of type unsigned long, the other operand will be converted to type of unsigned long; otherwise, if one of the operands is of type long , the other operand will be converted to type long; otherwise, if the type of one operand is unsigned, the other operand will be converted to type unsigned; otherwise, both operands will be converted to type int.

In C, the correct use of arithmetic operators and reasonable type conversion is one of the keys to writing efficient and correct programs. However, when dealing with complex problems, you need to pay more attention to the naming of variables to avoid variable name conflicts or difficult-to-understand variable names to improve the readability and maintainability of the program.

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