两个goroutine 循环打印1~10

今天面试遇到"两个goroutine 循环打印1~100" 思路是一个goroutine放数据,一个goroutine读数据,可是结果却是乱序的

func Test_0(t *testing.T) {
    //fmt.Println("123")
    c1 := make(chan int)
    wg := sync.WaitGroup{}
    wg.Add(2)
    go func() {
        for i := 0; i < 10; i += 2 {
            c1 <- 1
            fmt.Print(i)
        }
        wg.Done()
    }()
    go func() {
        for i := 1; i < 10; i += 2 {
            <-c1
            fmt.Print(i)
        }
        wg.Done()
    }()
    wg.Wait()
}

=== RUN Test_0 0132457689--- PASS: Test_0 (0.00s) PASS

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之后看了晚上的解答,只是循环的时候从+2->++,奇怪?这样就没问题呢?

func Test_dongchedi(t *testing.T) {
    //fmt.Println("123")
    c1 := make(chan int)
    wg := sync.WaitGroup{}
    wg.Add(2)
    go func() {
        for i := 1; i <= 10; i++ {
            c1 <- 1
            if i%2 == 1 {
                fmt.Print(i)
            }
        }
        wg.Done()
    }()
    go func() {
        for i := 1; i <= 10; i++ {
            <-c1
            if i%2 == 0 {
                fmt.Print(i)
            }
        }
        wg.Done()
    }()
    //c1 <- 1
    wg.Wait()
}

=== RUN Test_dongchedi 12345678910--- PASS: Test_0(0.00s) PASS