JavaScript long text concatenate

by edgardleal

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/highlight.js/8.6/highlight.min.js"></script>
<link rel="stylesheet" href="https://highlightjs.org/static/demo/styles/androidstudio.css">
<textarea name="source" id="" cols="30" rows="10"></textarea>
<textarea name="dest" readonly="true" id="" cols="30" rows="10"></textarea>
<pre>
    <code class="javascript hljs">
     
    </code>
</pre>

JavaScript

$(document).ready(function () {
    var source = $('textarea[name=source]'),
        dest = $('pre code.javascript'),
        dest_mem = $('textarea[name=dest]');

    source.keyup(function () {
        var text = this.value,
            lines = text.split(/\n/),
            result = 'var text = ',
            num_lines = lines.length;

        for (i in lines) {
            result += (i == 0 ? '' : '    ') + '"' + lines[i] + '"' + (num_lines - 1 <= i ? ';' : ' +') + '\n';
        }
        dest.text(result);
        dest_mem.val(result);
        hljs.highlightBlock(dest.get(0));
    });
});