Master Go Operators and Control Flow: A Practical Guide

Go Operators Overview

This article continues the Go language basics series, focusing on operators and control flow.

Arithmetic Operators

+

: addition -: subtraction *: multiplication /: division %: remainder ++: increment --: decrement

Relational Operators

==

: equal !=: not equal >: greater than >=: greater than or equal <: less than <=: less than or equal

Logical Operators

&&

: logical AND ||: logical OR !: logical NOT

Bitwise Operators

&

: bitwise AND |: bitwise OR ^: bitwise XOR <<: left shift >>: right shift

Assignment Operators

=

: simple assignment +=: add then assign -=: subtract then assign *=: multiply then assign /=: divide then assign %=: remainder then assign <<=: left shift then assign >>=: right shift then assign &=: bitwise AND then assign |=: bitwise OR then assign ^=: bitwise XOR then assign

Control Flow

Go provides the following control structures:

if (including else if and else)

switch case

for (standard, infinite, range)

goto (use with caution)

If Statement

Syntax:

if condition {
    // statements
} else if otherCondition {
    // statements
} else {
    // statements
}

Example:

package main

import "fmt"

func main() {
    var gender = "男"
    if gender == "男" {
        fmt.Println("男")
    } else if gender == "女" {
        fmt.Println("女")
    } else {
        fmt.Println("啥都不是???")
    }
}

Switch Case

Switch works like a series of if statements but is more concise.

package main

import "fmt"

func main() {
    var week = 3
    switch week {
    case 1:
        fmt.Println("周一")
    case 2:
        fmt.Println("周二")
    case 3:
        fmt.Println("周三")
    default:
        fmt.Println("未知")
    }
}

For Loop

Standard for loop:

for i := 0; i < 10; i++ {
    fmt.Println(i)
}

Infinite loop (use carefully):

for {
    fmt.Println("666")
}

Range loop for collections:

package main

import "fmt"

func main() {
    var student_list = [...]string{"张三", "李四", "王五"}
    for index, v := range student_list {
        fmt.Println(index, v)
    }
}

Goto

Goto jumps to a labeled statement; overuse can make code hard to follow.

package main

import "fmt"

func main() {
    for i := 0; i < 10; i++ {
        for j := 0; j < 10; j++ {
            if j == 2 {
                goto breakTag
            }
            fmt.Printf("%v-%v
", i, j)
        }
    }
breakTag:
    fmt.Println("结束for循环")
}

Summary

This article covered Go's basic operators and control flow structures, providing explanations and runnable code examples to help beginners write correct Go programs.