Question

我需要做一个简单的for循环，使它最终看起来像这样：

1****** 12***** 123**** 1234*** 12345** 123456* 1234567

到目前为止，我写道：

for (i = 1; i <= 7; ++i) {
    document.write(i);
    for (j = 1; j < 7; j++) {
        if (j <= 7) {
            document.write("*");
        } else {
            document.write("&nbsp");
        }
    }
}

Answer 1

你需要另一个变量来保存循环中迭代的数字。

for (i = 1, k = ""; i <= 7; ++i) {
  k += i;  // concatenating i variable values in k variable
  document.write(k);
  for (j = i; j < 7; j++) {
    document.write("*");
  }
  document.write("&nbsp");
}

Answer 2

你快到了那里：

for (i = 1; i <= 7; ++i) {
    for (j = 1; j <= 7; j++) {
        if (j <= i)
            document.write(j);
        else
            document.write("*");
    }
    document.write("&nbsp;");
}

您的评论代码：

for (i = 1; i <= 7; ++i) { // This for should loop over your blocks
    document.write(i); // Doing this will make the first number change for every block.
    for (j = 1; j < 7; j++) {  // This for should loop over your numbers
        if (j <= 7) { // This if is only there for the space? Put it in the other loop!
            document.write("*"); 
        } else {
            document.write("&nbsp");
        }
        // Here you should check if you want a * or a number. Not the check to see if you want a space or not.
    }
    // Space should be here.
}

Answer 3

你不远，有几项改变应该这样做：

＆＃13;

for (i = 1; i <= 7; i++) {
  for (j = 1; j <= 7; j++) {
    if (j <= i)
      document.write(j);
    else
      document.write("*");
  }
  document.write("&nbsp");
}

＆＃13;

Answer 4

试试这个：首先，你有一个从1到7的主循环，然后你有第二个循环写你的字符串，所以从1开始，直到我你正在写数字然后添加** 这是jsfiddle

 for (i=1;i<=7;i++)
{
     for(j=1; j<=i; j++)
    document.write(j);
    {
       while(j<=7)
       {
           document.write("*");
           j++;
       }
           document.write("&nbsp");
    }
}

用于生成带星号的数字的循环

4 个答案: