第02天(函数、工程管理)_02

06_多个返回值.go

package main //必须
import "fmt"
//多个返回值
func myfunc01() (int, int, int) {
    return 1, 2, 3
}
//go官方推荐写法
func myfunc02() (a int, b int, c int) {
    a, b, c = 111, 222, 333
    return
}
func myfunc03() (a, b, c int) {
    a, b, c = 111, 222, 333
    return
}

func main() {
    //函数调用
    a, b, c := myfunc02()
    fmt.Printf("a = %d, b = %d, c = %d\n", a, b, c)
}

07_有参有返回值.go

package main //必须
import "fmt"
//函数定义
func MaxAndMin(a, b int) (max, min int) {
    if a > b {
        max = a
        min = b
    } else {
        max = b
        min = a
    }
    return //有返回值的函数，必须通过return返回
}
func main() {
    max, min := MaxAndMin(10, 20)
    fmt.Printf("max = %d, min = %d\n", max, min)
    //通过匿名变量丢弃某个返回值
    a, _ := MaxAndMin(10, 20)
    fmt.Printf("a = %d\n", a)
}

08_普通函数的调用流程.go

package main //必须

import "fmt"

func funcc(c int) {
    fmt.Println("c = ", c)
}

func funcb(b int) {
    funcc(b - 1)
    fmt.Println("b = ", b)
}

func funca(a int) {
    funcb(a - 1)
    fmt.Println("a = ", a)
}

func main() {
    funca(3) //函数调用
    fmt.Println("main")
}

09_函数递归调用的流程.go

package main //必须
import "fmt"
func test(a int) {
    if a == 1 { //函数终止调用的条件，非常重要
        fmt.Println("a = ", a)
        return //终止函数调用
    }
    //函数调用自身
    test(a - 1)
    fmt.Println("a = ", a)
}
func main() {
    test(3)
    fmt.Println("main")
}

10_数字累加.go

package main //必须

import "fmt"

//实现1+2+3+……100
func test01() (sum int) {
    for i := 1; i <= 100; i++ {
        sum += i
    }

    return
}

func test02(i int) int {
    if i == 1 {
        return 1
    }

    return i + test02(i-1)
}

func test03(i int) int {
    if i == 100 {
        return 100
    }

    return i + test03(i+1)
}

func main() {
    var sum int
    //sum = test01()
    //sum = test02(100)
    sum = test03(1)
    fmt.Println("sum = ", sum)

}