Go Tutorial
Go Useful Resources
Selected Reading
- Go - 错误处理
- Go - Interfaces
- Go - 类型转换
- Go - 递归
- Go - Maps
- Go - 范围
- Go - 切片
- Go - 结构
- Go - 指针
- Go - 数组
- Go - 字符串
- Go - 作用域
- Go - 函数
- Go - 循环
- Go - 条件判断
- Go - 操作符
- Go - 常量
- Go - 变量
- Go - 数据类型
- Go - 基本语法
- Go - 程序结构
- Go - 环境设置
- Go - 概述
- Go - Home
Go Useful Resources
Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
Go - 操作符
Go - 操作符
运算符是一个符号，告诉编译器执行特定的数学或逻辑操作。Go语言有丰富的内置运算符，并提供以下类型的运算符-
算术运算符
关系运算符
逻辑运算符
位运算符
赋值运算符
混杂运算符
本教程逐一解释算术、关系、逻辑、逐位、赋值和其他运算符。
Arithmetic Operators
下表显示了Go语言支持的所有算术运算符。假设变量A保持10，变量B保持20，则−
| Operator | Description | Example |
|---|---|---|
| + | Adds two operands | A + B gives 30 |
| - | Subtracts second operand from the first | A - B gives -10 |
| * | Multippes both operands | A * B gives 200 |
| / | Divides the numerator by the denominator. | B / A gives 2 |
| % | Modulus operator; gives the remainder after an integer spanision. | B % A gives 0 |
| ++ | Increment operator. It increases the integer value by one. | A++ gives 11 |
| -- | Decrement operator. It decreases the integer value by one. | A-- gives 9 |
Relational Operators
The following table psts all the relational operators supported by Go language. Assume variable A holds 10 and variable B holds 20, then −
下表列出了Go语言支持的所有关系运算符。假设变量A保持10，变量B保持20，则−
| Operator | Description | Example |
|---|---|---|
| == | It checks if the values of two operands are equal or not; if yes, the condition becomes true. | (A == B) is not true. |
| != | It checks if the values of two operands are equal or not; if the values are not equal, then the condition becomes true. | (A != B) is true. |
| > | It checks if the value of left operand is greater than the value of right operand; if yes, the condition becomes true. | (A > B) is not true. |
| < | It checks if the value of left operand is less than the value of the right operand; if yes, the condition becomes true. | (A < B) is true. |
| >= | It checks if the value of the left operand is greater than or equal to the value of the right operand; if yes, the condition becomes true. | (A >= B) is not true. |
| <= | It checks if the value of left operand is less than or equal to the value of right operand; if yes, the condition becomes true. | (A <= B) is true. |
Logical Operators
下表列出了Go语言支持的所有逻辑运算符。假设变量A保持1，变量B保持0，则−
| Operator | Description | Example |
|---|---|---|
| && | Called Logical AND operator. If both the operands are non-zero, then condition becomes true. | (A && B) is false. |
| || | Called Logical OR Operator. If any of the two operands is non-zero, then condition becomes true. | (A || B) is true. |
| ! | Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false. | !(A && B) is true. |
The following table shows all the logical operators supported by Go language. Assume variable A holds true and variable B holds false, then −
| Operator | Description | Example |
|---|---|---|
| && | Called Logical AND operator. If both the operands are false, then the condition becomes false. | (A && B) is false. |
| || | Called Logical OR Operator. If any of the two operands is true, then the condition becomes true. | (A || B) is true. |
| ! | Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true, then Logical NOT operator will make it false. | !(A && B) is true. |
Bitwise Operators
逐位运算符处理位并执行逐位运算。&、|和^的真值表如下-
| p | q | p & q | p | q | p ^ q |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 0 |
| 1 | 0 | 0 | 1 | 1 |
Assume A = 60; and B = 13. In binary format, they will be as follows −
A = 0011 1100
B = 0000 1101
-----------------
A&B = 0000 1100
A|B = 0011 1101
A^B = 0011 0001
~A = 1100 0011
The Bitwise operators supported by C language are psted in the following table. Assume variable A holds 60 and variable B holds 13, then −
下表列出了C语言支持的位运算符。假设变量A保持60，变量B保持13，则−
| Operator | Description | Example |
|---|---|---|
| & | Binary AND Operator copies a bit to the result if it exists in both operands. | (A & B) will give 12, which is 0000 1100 |
| | | Binary OR Operator copies a bit if it exists in either operand. | (A | B) will give 61, which is 0011 1101 |
| ^ | Binary XOR Operator copies the bit if it is set in one operand but not both. | (A ^ B) will give 49, which is 0011 0001 |
| << | Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand. | A << 2 will give 240 which is 1111 0000 |
| >> | Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand. | A >> 2 will give 15 which is 0000 1111 |
Assignment Operators
The following table psts all the assignment operators supported by Go language −
| Operator | Description | Example |
|---|---|---|
| = | Simple assignment operator, Assigns values from right side operands to left side operand | C = A + B will assign value of A + B into C |
| += | Add AND assignment operator, It adds right operand to the left operand and assign the result to left operand | C += A is equivalent to C = C + A |
| -= | Subtract AND assignment operator, It subtracts right operand from the left operand and assign the result to left operand | C -= A is equivalent to C = C - A |
| *= | Multiply AND assignment operator, It multippes right operand with the left operand and assign the result to left operand | C *= A is equivalent to C = C * A |
| /= | Divide AND assignment operator, It spanides left operand with the right operand and assign the result to left operand | C /= A is equivalent to C = C / A |
| %= | Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operand | C %= A is equivalent to C = C % A |
| <<= | Left shift AND assignment operator | C <<= 2 is same as C = C << 2 |
| >>= | Right shift AND assignment operator | C >>= 2 is same as C = C >> 2 |
| &= | Bitwise AND assignment operator | C &= 2 is same as C = C & 2 |
| ^= | bitwise exclusive OR and assignment operator | C ^= 2 is same as C = C ^ 2 |
| |= | bitwise inclusive OR and assignment operator | C |= 2 is same as C = C | 2 |
Miscellaneous Operators
There are a few other important operators supported by Go Language including sizeof and ?:.
| Operator | Description | Example |
|---|---|---|
| & | Returns the address of a variable. | &a; provides actual address of the variable. |
| * | Pointer to a variable. | *a; provides pointer to a variable. |
Operators Precedence in Go
运算符优先级决定表达式中术语的分组。这会影响表达式的求值方式。某些运算符的优先级高于其他运算符；例如，乘法运算符具有比加法运算符更高的优先级。
例如，x=7+3*2；这里，x被赋值为13，而不是20，因为运算符*的优先级高于+，所以它首先与3*2相乘，然后加成7。
在这里，优先级最高的运算符出现在表的顶部，优先级最低的运算符显示在表的底部。在表达式中，将首先计算优先级较高的运算符。
| Category | Operator | Associativity |
|---|---|---|
| Postfix | () [] -> . ++ - - | Left to right |
| Unary | + - ! ~ ++ - - (type)* & sizeof | Right to left |
| Multippcative | * / % | Left to right |
| Additive | + - | Left to right |
| Shift | << >> | Left to right |
| Relational | < <= > >= | Left to right |
| Equapty | == != | Left to right |
| Bitwise AND | & | Left to right |
| Bitwise XOR | ^ | Left to right |
| Bitwise OR | | | Left to right |
| Logical AND | && | Left to right |
| Logical OR | || | Left to right |
| Assignment | = += -= *= /= %=>>= <<= &= ^= |= | Right to left |
| Comma | , | Left to right |