Javascript/JQuery:如何统计用逗号分隔的单词？

Question

使用Javascript:

$(document).ready(function()
{
    $('#field').keyup(function()
    {
        var count = '??';

        $('#count').html(count);
    });
});

HTML:

<input type="text" id="field" /> <span id="count">5</span>

示例(单词始终用逗号分隔):

example 1: word, word word
count: (5 - 2) = 3

example 2: word
count: (5 - 1) = 4

example 3: word, word,
count: (5 - 2) = 3

example 4: word, word, word
count: (5 - 3) = 2

因此,我需要计算用逗号分隔的单词数量,但是例如如示例3所示,只有当逗号后面还有单词时,才应将它们计为3个单词.

并且不应允许用户输入超过5个单词.

Answer 1

就像是:

$("#input").keyup(function(){
    var value = $(this).val().replace(" ", "");
    var words = value.split(",");

    if(words.length > 5){
        alert("Hey! That's more than 5 words!");
        $(this).val("");
    }
});

jsFiddle示例:http://jsfiddle.net/BzN5W/

编辑:

更好的例子:http://jsfiddle.net/BzN5W/2/

$("#input").keypress(function(e){
    var value = $(this).val().replace(" ", "");
    var words = value.split(",");

    if(words.length > 5){
        //alert("Hey! That's more than 5 words!");
        e.preventDefault();
    }
});