The for loop in Go language realizes multiple loop control through a unified structure, and its core is three parts: initialization, conditional judgment and post-operation. 1. The basic structure is suitable for scenarios with known number of loops, such as traversing arrays or slice indexes; 2. Range can traverse collection type data in concisely, which is commonly used to process HTTP request parameters, configuration items and string characters; 3. Go simulates the while loop behavior by omitting initialization and post-statement, and supports infinite loops to cope with polling, listening and other needs; 4.break is used to exit the loop, and continue skips the current iteration. The two need to be used reasonably in nested loops or complex condition filtering to keep the logic clear. Mastering these typical uses can create efficient and easy-to-read Go programs.
for
loops in Go are the core structure for handling repeated operations. It does not have multiple loop forms (such as while
, do-while
) like other languages, but implements all types of loop control through flexible for
syntax. Mastering its use is very important for writing a Go program well.

Basic for loop structure
The basic for
loop in Go contains three parts: initialization statement, conditional expression and post-statement. They are separated by semicolons and written in brackets after the for
keyword.

for i := 0; i < 5; i { fmt.Println(i) }
This code prints out numbers from 0 to 4.
in:
-
i := 0
is the initialization statement, executed once before the loop starts. -
i < 5
is a conditional judgment, and it will be checked before each cycle. -
i
is the operation that runs after each cycle body is executed.
This structure is most commonly used in scenarios where the number of loops is known, such as traversing an array or a slice's index.

Iterate over arrays, slices, and strings
In Go, you can use range
and for
to traverse the data structure of collection type. This method is simple and not prone to errors.
nums := []int{1, 2, 3, 4, 5} for index, value := range nums { fmt.Printf("Index: %d, value: %d\n", index, value) }
If you don't need indexes or values, you can use _
the unnecessary parts:
for _, value := range nums { fmt.Println(value) }
Common uses include:
- List of parameters for processing HTTP requests
- Traversal configuration items
- String characters are processed one by one
When traversing a string, value
will be of type rune
, which is suitable for processing multi-byte characters such as Chinese.
Simulate the behavior of while loops
Go does not have a separate while
keyword, but similar behavior can be simulated by omitting initialization and post-statements:
i := 0 for i < 5 { fmt.Println(i) i }
This is equivalent to other languages:
let i = 0; while (i < 5) { console.log(i); i ; }
You can also construct an infinite loop:
for { // Execute some logic if someCondition { break } }
This situation is often used in scenarios where polling, listening to events, reading stream data, etc. need to be continuously run.
Control loop flow: break and continue
In the loop body, break
is used to exit the loop early, while continue
skips the current iteration and goes directly to the next round.
For example:
for i := 0; i < 10; i { if i%2 == 0 { Continue continue } fmt.Println(i) // Print only odd numbers}
Some practical tips:
-
break
out of outer loop using tagged break in nested loop - Use
continue
to skip invalid or unprocessed data - Complex condition filtering with
switch
statement
Be careful not to abuse break
and continue
, otherwise the logic will be difficult to understand.
Basically these common uses. Although Go's for
loop is unified in form, it is flexible enough to adapt to most scenarios. As long as you are familiar with several typical writing methods, you can write clear and efficient circular logic.
The above is the detailed content of golang for loop examples. For more information, please follow other related articles on the PHP Chinese website!

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