Question

在一个简单的HTML脚本中，我有两个元素：textarea和一个不起作用的Javascript脚本（如下）。我的目标是只从textarea中选择UP TO前5个非空行（每行由\ n分割）。这段代码：

var textarea = document.getElementbyId（＆＃39; data＆＃39;）。value;

从textarea中选择所有（10）行，但我只想选择最多5行并忽略其余行。我把我的工作尝试放在这里 - http://jsfiddle.net/1xst7e22/

TEXTAREA

<textarea id="data" style="width:100%;height:300px">
January
February

March
April
May
June
July
August
September
October
November
December
</textarea>

JAVASCRIPT （这是我悲惨的尝试，没有工作......）：假设x = 5：

function getLines (x)
{
var textarea = document.getElementbyId('data');
var firstX = (textarea.value ? textarea.value + "\n" : "");

      if (firstX.length > x) firstX = firstX.slice(x);

      textarea.value = firstX.join("\n");
}

-

因此，当脚本正常工作时，textarea = document.getElementbyId（＆＃39; data＆＃39;）。value;应该只持有以下几行：

January
February
March
April
May

Answer 1

试试这段代码：

   function getLines(x) { 
        var textarea = document.getElementById('data'); 
        var firstX = textarea.innerHTML.split("\n").slice(0,x).join("\n")
        textarea.value = firstX;
    }

Answer 2

var data = document.getElementById('data');
var dataArray = data.value.split("\n");
dataArray = dataArray.slice(0,5);
data.value = dataArray.join("\n");

<textarea id="data" style="width:100%;height:300px">
January
February
March
April
May
June
July
August
September
October
November
December
</textarea>

Javascript - 只选择textarea中的前5个非空行

2 个答案: