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我正在尝试使用 javascript 关闭标签，但是当它写入文档时，正斜杠总是丢失。我试过在它前面加上一个反斜杠（“\/”），但它似乎有帮助。我一直<pre>在页面源上看到。这是代码：

var temp_index = 0,
    line_count = 0;
while (temp_index < text.length) {
    if ((text.charAt(temp_index) == "\n") && (line != line_count)) {
        if (line_count < line) line_count++;
        if (line_count == line) {
            text = text.substring(0, temp_index) + "<pre id='line'>" + text.substring(temp_index);
            temp_index++;
            while ((text.charAt(temp_index) != "\n") && (temp_index < text.length)) temp_index++;
            text = text.substring(0, temp_index - 1) + "<\pre>" + text.substring(temp_index);
        }
    }
    temp_index++;
}
return text;

我期望得到：

Heres's the last line
<pre id='line'>Here's the current line</pre>
Here's the next line
Here's the final line

但我得到：

Here's the last line
<pre id='line'>Here's the current line
Here's the next line
Here's the final line</pre>

我通过用标签替换行尾的 \n 来快速修复。即使它解决了这个问题，它也会导致键盘输入出现错误。这是更新的代码。

if (line_count == line) {
    text = text.substring(0, temp_index) + "<pre id=\"line\">" + text.substring(temp_index);
    temp_index++;
    while ((text.charAt(temp_index) != "\n") && (temp_index < text.length)) temp_index++;
    text = text.substring(0, temp_index - 1) + "</pre>" + text.substring(temp_index);
    break;
}
4

1 回答 1

1

这段代码在语法上是正确的——初始化temp_index并text省略break了循环的外部：

temp_index = 0;
text = "this is \n a test \n of some info";

text =  text.substring( 0, temp_index )
     + "<pre id=\"line\">"
     + text.substring( temp_index );

temp_index++;

while( ( text.charAt( temp_index ) != "\n" ) && ( temp_index < text.length ) ) temp_index++;

text = text.substring( 0, temp_index - 1 )
     + "</pre>"
     + text.substring( temp_index - 1 );

alert(text);

结果是

<pre id="line">this is</pre> 
 a test 
 of some info

您还可以使用replace重写当前行并获得与上述相同的结果：

text = "this is \n a test \n of some info";
text = text.replace(/(.+?)\n/, "<pre id=\"line\">$1</pre>\n");

如果您知道当前行并且想在它前面加上它<pre id=\"line\">，</pre我会使用split()and join()：

// update line 2
line = 2;

// sample text
text = "this is\n"+
       "a test\n"+
       "of some info";

// split to an array on newlines
vals = text.split("\n");

// replace the second line, which has an index of 1 (or line-1)
vals[line-1] = "<pre id=\"line\">" + vals[line-1] + "</pre>";

// join back to an array using newlines
text = vals.join("\n");

结果：

this is
<pre id="line">a test</pre>
of some info
于 2013-04-01T07:44:29.720 回答