Golang (also known as Go) is an open source programming language released by Google in 2009. Its design is inspired by the C language, but has made many improvements and innovations, so it has higher efficiency, security and concurrency. When learning Golang language, it is very important to understand the meaning of various symbols. This article will introduce in detail the meaning of common symbols in Golang language.
1. Comment symbols
Comment symbols have their uses in any programming language. They are used to explain the code, mark the code, remind yourself or other developers, etc. Golang supports single-line comments as well as multi-line comments.
Single-line comments: Add two slashes (//) before the code, followed by the comment content.
As shown below:
// This is a single line comment
Multi-line comments: Add "/" and "/" symbols before and after the comment content.
As shown below:
/* This is a multi-line comment */
2. Function declaration
In Golang, function declaration is made using the func keyword. For example, a function named add is declared as follows:
func add(x int, y int) int { return x + y }
where add is the function name, x and y are the parameter names, and int represents the type of the return value.
3. Variable assignment
In Golang, a variable can be assigned the value of another variable or the result of any expression. The assignment symbol is =.
For example:
x := 5 y := x + 3
In this example, x is assigned the value 5, and y is assigned the result of x 3, which is 8. It should be noted that in Golang, the type of a variable can be deduced through expressions. For example, in the above example, x is deduced as an integer type.
4. Operators
In Golang, there are many operators, including arithmetic, comparison, logic, etc.
Arithmetic operators include plus sign ( ), minus sign (-), multiplication sign (*), division sign (/) and modulo (%).
Comparison operators include equal (==), not equal (!=), greater than (>), less than (<), greater than or equal to (>=) and less than or equal to (<=) .
Logical operators include logical AND (&&), logical OR (||) and logical NOT (!).
5. Control statements
In Golang, control statements include conditional statements and loop statements.
Conditional statements include if, else if and else. if and else if must be followed by a conditional expression. If the result of the conditional expression is true, then the program will execute the code in the statement block. If the conditional expression in the if statement block is not satisfied, the program will execute the next else if or the final else.
Loop statements include for loops and range loops. There are three ways of for loop: initialization, condition, and post-statement; when the condition statement is true, the loop body will continue to execute. Range loops can iterate over a collection, such as arrays, slices, and maps.
6. Pointers
In Golang, a pointer is a special type of variable that stores the memory address of the variable. Golang provides two operators to access pointers: & and. The & operator is used to obtain the memory address of a variable, and theoperator is used to access the variable pointed to by the pointer.
For example:
x := 5 p := &x //取x的地址 fmt.Println(*p) //通过指针p访问x的值
In the above example, get the address of x through &p and store it in the pointer p. Then, the value of the variable pointed to by pointer p (that is, x) is accessed through *p, which is 5 in this example.
7. Reference types
Golang has two reference types: slice and map. A slice is a dynamic array that can add or delete elements. A map is a collection of key-value pairs that can also be added or deleted.
For example:
// 创建一个切片 s := make([]int, 3) // 添加元素 s = append(s, 1) // 创建一个映射 m := make(map[string]int) // 添加键值对 m["one"] = 1
The above are some common symbols and their meanings in the Golang language. With these basic understandings, we can better understand and write Golang code.
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