// for循環
func loop1() {
    sum := 0
    for i := 0; i < 100; i++ {
        sum += i
    }
    fmt.Printf("sum = %d\n", sum)
 
    // 和while循環一樣
    sum1 := 3
    for sum1 <= 10 {
        sum1 += sum1
    }
    fmt.Printf("sum1 = %d\n", sum1)
}

// for-each使用
func loop2() {
    strs := []string{"小王", "小明"}
    for i, str := range strs {
        fmt.Printf("%v今天第%d次去核酸\n", str, i)
    }
    nums := [6]int{1, 2, 4, 6}
    for i, num := range nums {
        fmt.Printf("%d - %d\n", i, num)
    }
}

// break
func loop3() {
    var a int = 0
    var b int = 30
    for b > 0 {
        if a > 4 {
            break
        }
        a++
        b -= 3
    }
    fmt.Printf("a=%d,b=%d\n", a, b)
    var c int = 0
    var d int = 30
    for i := 0; i < 10; i++ {
        c++
        for j := 0; j < 10; j++ {
            if d < 0 {
                break
            }
            d--
        }
    }
    fmt.Printf("c=%d,d=%d\n", c, d)
    c = 0
    d = 30
loop1:
    for i := 0; i < 10; i++ {
        c++
        for j := 0; j < 10; j++ {
            if d < 0 {
                break loop1
            }
            d--
        }
    }
    fmt.Printf("c=%d,d=%d\n", c, d)
}

// continue
func loop4() {
    var c int = 0
    var d int = 30
    for i := 0; i < 10; i++ {
        c++
        for j := 0; j < 10; j++ {
            d--
            if d < 0 {
                continue
            }
        }
    }
    fmt.Printf("c=%d,d=%d\n", c, d)
    c = 0
    d = 30
loop1:
    for i := 0; i < 10; i++ {
        c++
        for j := 0; j < 10; j++ {
            d--
            if d < 0 {
                continue loop1
            }
        }
    }
    fmt.Printf("c=%d,d=%d\n", c, d)
}

//goto
func loop5() {
    m := 0
loop1:
    for m < 20 {
        fmt.Printf("loop1 -> %d\n", m)
        if m > 3 {
            break loop1
        }
        i := 0
    loop2:
        for i < 10 {
            i++
            if i == 5 {
                goto loop2
            }
            fmt.Printf("loop2 -> %d\n", i)
        }
        m++
    }
 
}