golang for usage

Go language (also known as Golang) is an open source programming language developed by Google. Since its release, this language has become one of the preferred languages ​​in web and cloud computing development. Because it has the advantages of efficiency, safety, easy to learn, lightweight and platform independent. Among them, the for statement is one of the important components of Golang. This article will introduce the usage and examples of for in Golang.

I. The basic syntax of the for statement

The for statement in Golang is basically the same as that in other languages: including conditional statements, loop variables, and loop bodies. The basic syntax of for in Golang is as follows:

for 初始化语句; 条件语句; post语句 {
    // 执行语句
}

Among them, Initialization statement is used to initialize a loop counter and declare one or more condition variables, which can be used in the for statement Use; Conditional statement is used to specify the termination condition of the loop. If the condition is not true, the loop will end; post statement is the statement or operation to be executed after the loop is executed, usually directly or indirectly Operateloop counter.

II. for loop example

1. Simple example of for statement

The following is a simple for example for printing numbers from 0 to 4:

for i := 0; i < 5; i++ {
    fmt.Println(i)
}

In this for statement, the initialization statement i := 0 is to set the initial value of the loop counter; the conditional statement i < 5 determines whether the loop counter is less than 5, and if so, Then continue to execute the loop; i adds 1 to the counter after each loop.

2. For statement nesting example

In Golang, for loops can also be nested. Here is a simple example for printing the multiplication table:

for i := 1; i <= 9; i++ {
    for j := 1; j <= i; j++ {
        fmt.Printf("%d * %d = %d ", j, i, i*j)
    }
    fmt.Println()
}

In this example, the outer loop goes from 1 to 9, and another loop is done inside the loop, from 1 to the value of the outer loop counter i. The inner loop then controls the number of times the "*" expression is printed. Finally, after each printing, a line feed operation is performed.

3. Example of for range statement

Another for loop is the for range loop, which can iteratively discover arrays, slices, strings, maps, and channels (Canal) and user-defined types, etc. Here is a simple for range loop example for iterating over the elements in a slice:

numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
for i, num := range numbers {
    fmt.Printf("Index %d, Value: %d\n", i, num)
}

In this example, initialize numbers to a slice of integers. for range The loop uses two variables, i and num, to iterate through each element in the array and print the index and value on each iteration of the loop.

4. for infinite loop example

Sometimes, we need to use an infinite loop to perform some tasks. At this time, you can use Golang's for infinite loop. Here is an example of using an infinite loop:

for {
    // 执行代码块
}

In this example, use the for statement to create an infinite loop. When the conditional statement is omitted, the loop will continue executing until the program is interrupted or exits.

III. Summary

The basic syntax of for in Golang is similar to other programming languages. The initialization, conditional control and loop body of the for loop statement are highly flexible. For Golang programmers, using a variety of for loop usages will make the program read clearer and more powerful.

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