Question

我正在尝试使用for循环播放儿童歌曲“墙上挂着10个绿色瓶子”。因此，我从10开始循环播放，然后从0开始播放。应该将文字加起来，最后显示全部歌曲

对于i = 10 i = 0 i--，循环内的文本。数字应该在变化，但是其余的应该保持不变

   

 <div id="demo"></div>

    <script>
      function favsong() {
        var i;
        var song = "";
        var poem = "green bottles, hanging on a wall";
        var poem1 ="If 1 green bottle were to accidentally fall. There'd be";
        
        for (i=10;i=0;i--) {
          song+=i+poem+"<br>"+i+poem+"<br>"+poem1;  
          if (i==1){
song+="1 green bottle hanging on the wall"+"<br>+"1 green bottle hanging on the wall"
continue
}
        }
document.getElementById("demo").innerHTML = song;
      }
    </script>

10 green bottles, hanging on a wall,
10 green bottles, hanging on a wall,
If 1 green bottle were to accidentally fall
There'd be 9 green bottles, hanging on the wall
9 green bottles, hanging on a wall,
9 green bottles, hanging on a wall,
If 1 green bottle were to accidentally fall
There'd be 8 green bottles, hanging on the wall
8 green bottles, hanging on a wall,
8 green bottles, hanging on a wall,
If 1 green bottle were to accidentally fall
There'd be 7 green bottles, hanging on the wall
... and so on...
1 green bottles, hanging on a wall,
1 green bottles, hanging on a wall,
If 1 green bottle were to accidentally fall
There'd be 0 green bottles, hanging on the wall

Answer 1

更新您的for循环键入错误，以使用library(dplyr) df1 %>% slice(tail(row_number(), 5))代替i--。

另一个问题是在双引号中使用tall和"poem"，这意味着它是一个字符串，因此在循环中不使用song和poem的实际值。

"poem1 "

function text1() {
    var i= 0;
    var song = "";
    var poem = " green bottles, hanging on a wall";
    var poem1 = "if 1 green bottle were to accidentally fall. There'd be "
    
    for (i = 10; i > 0; i--) {
      song += i + poem + "<br>" + i +"" + poem + "<br>" + poem1 + "";  
      document.getElementById("demo").innerHTML = song;
    }
  }
  
  text1();

Answer 2

显示零个没有poem1的瓶子。还使用模板文字来提高可读性。

<div id="demo"></div>

<script>
  function text1() {

    var i;
    var song = "";
    var poem = "green bottles, hanging on a wall\n";
    var poem1 = "if 1 green bottle were to accidentally fall. There'd be\n"

    for (i = 10; i >= 0; i--) {
        song += `${i} ${poem}${i} ${poem}`
        if(i) {song += poem1}
    }
    document.getElementById("demo").innerHTML = song;
 }
</script>

使用循环播放重复的歌曲

2 个答案: