问在鼠标上方突出显示单行

EN

var
    //Keeps the content (individual spans) as they are built.
    $keeper = $("<div>"),
    //Used to measure span width for comparison to container.
    $measurer = $("<div>"),
    //The container of the text content
    $p = $("p"),
    //An individual line of the content
    $line = $("<span>").appendTo($measurer),

//make this "invisible," but allow for measurement against container width
//with no restriction on measurer's own width (fixed)
$measurer.css({'position': 'fixed', 'top': '100%'}).appendTo("body");

//Iterate through each "word" derived from splitting on any space.
$p.text().split(/\s/).forEach(function (elem) {
    //Start forming line text.  Don't forget word spacing
    $line.text($line.text() + elem + ' ');

    //Enough words to make the line width longer than the p width.
    //This indicates the end of "line."
    if ($line.width() > $p.width()) {
        //Remove the last word.
        $line.text(function (_, text) {
            return text.slice(0, text.lastIndexOf(elem));
        });

        //Keep the currently formed line to add back later
        $line.appendTo($keeper);

        //Create a new line for measuring
        $line = $("<span>");
        $line.text(' ' + elem).appendTo($measurer);
    }
});
//Append any leftover words not big enough to form a whole line
$keeper.append($measurer.html());
//Add back content
$p.html($keeper.html());
//cleanup
$keeper.remove();
$measurer.remove();

span:hover{
  background-color: #ccc;
}

// extract the text
var paragraph = $("#text").text();
// split the text into lines by searching for linebreaks
var lines = paragraph.split(/\r?\n/);
// clear the original text
$("#text").text('');
$.each(lines,function(index,elem){
  if (elem != ''){
    // for each line, wrap it with a span and bring back the linebreak
    $("#text").append('<span>'+elem+'</span><br/>');      
  }
});

span:hover { background:#DDD }