javascript自动获取标题中的关键词

新闻标题：<
input type="
text"
size="
50"
name="
keywords"
id="
keywords"
/>

<
br />
<
br />

<
input type="
button"
onclick="
lastIndexDemo()
"
 
value="
提取关键词"
/>
<
br />

<
br />
<
input type="
text"
size="
50"
name="
tags"
id="
tags"
/>

<
script>

var keylis = new Array("
贸易"
,"
制裁"
,"
改造"
,"
中国"
,"
经济"
,"
美国"
,"
银行"
,"
速度"
,"
机电"
,"
进出口"
,"
商会"
,"
彩电"
,"
税率"
,"
国家"
,"
家电"
,"
电信"
,"
产业"
,"
电子"
,"
信息"
,"
产销"
,"
俄罗斯"
,"
检察官"
,"
检察"
,"
调查"
,"
欧盟"
,"
争端"
,"
投资"
,"
受挫"
,"
改革"
,"
实行"
,"
临时"
,"
价格"
,"
季度"
,"
扬言"
,"
演示简单"
,"
后台"
,"
工业"
,"
电器"
)

var keydrop="
"


function delHtmlTag(str)

{
return str.replace(/<
[^>
]+>
/g,"
"
)
//去掉所有的html标记
}
function lastIndexDemo(a)

{
var str = delHtmlTag(document.getElementById("
keywords"
).value)
//获取字符串
var keys = new Array
//词表存储序列
var titles = new Array

var key = new Array
//关键词对象存储序列
var gotkey = new Array()
//关键词对象
var name = new Array()
//关键词name
var address = new Array()
//关键词在词表中位置
var times = new Array()
//关键词在本篇目中的出现次数
var tfx = new Array()
//关键词tfx值
var stopkey = new Array()
//关键词是否为停用词
var desc = new Array()
//关键词排名
var strkey
// 声明变量预存关键字
var strl = str.length
//获取字符串长度
getkeywords(keys,titles)
//初始化关键词表和标题序列
getkey(str,strkey,strl,keys,key,name,address,stopkey)
//获取关键词，词表位置，是否停用
timesn(times,address)
//获取n（出现多少次）
gettfx(times,tfx)

toobject(key,address,times,tfx,stopkey,name)

outresult(key,address,times,tfx,stopkey,name,str)

}
function getkeywords(keys,titles)
{
var titl = 1

var keyl = keylis.length

var keyd = keydrop.length

for(i=0
i<
keyl
i++)
{
keys[i] = keylis[i]

}
for(i=0
i<
keyd
i++)
{
keys[i+keyl] = keydrop[i].childNodes[0].nodeValue

}
for(i=0
i<
titl
i++)
{
titles[i] = document.getElementById("
keywords"
).value

}
}
function timesn(times,address)
{
var k = 0

for(i=0
i<
address.length
i++)

{
for(j=0
j<
address.length
j++)

{
if(address[i] == address[j])

{k = k+1
}
}
times.push(k)

k = 0

}
}
function gettfx(times,tfx)
{
var k = Math.log(10)

var l

var j

var m

var n

for(i=0
i<
times.length
i++)

{
l = times[i]/1

j = Math.log(l)

n = times[i]*j

tfx.push(n.toFixed(3))

}
}
function toobject(key,address,times,tfx,stopkey,name)
{
var gotdkey = new Array

key["
name"
] = name

key["
address"
] = address

key["
tfx"
] = tfx

key["
stopkey"
] = stopkey

key["
times"
] = times

}
function getkey(str,strkey,strl,keys,key,name,address,stopkey)
{
for(k=strl
k>
0
k--)
{//控制循环次数
label:
for(j=6
j>
0
j--)//通过最大关键字长度控制循环

{
var strkey = str.substr(k-j, j)

//确定预检索字符串 strl-j 是位置 j是长度
for(i=0
i<
keys.length
i++)//通过关键字字库的数量确定循环次数

{
if(keys[i]==strkey)
{//如果现有关键字与字库匹配
name.push(strkey)

address.push(i)

if(i>
keylis.length)
{
stopkey.push(false)

}
else
{
stopkey.push(true)

}
k-=j

k++

break label

}
}
}
}
}
function outresult(key,address,times,tfx,stopkey,name,str)
{
var outtags = document.getElementById("
tags"
)

var indesc = 100

var intfx = "
"


var outkeyarray = new Array()

var outwordarray = new Array()

var outtfxarray = new Array()

for(i=0
i<
name.length
i++)

{
if(key["
stopkey"
][i] == true)

{outkeyarray.push(key["
name"
][i])

outtfxarray.push(key["
tfx"
][i])
}
}
for(i=0
i<
outkeyarray.length
i++)

{
for(j=outkeyarray.length
j>
i
j--)

{
if(outkeyarray[i] == outkeyarray[j])

{
outkeyarray = outkeyarray.slice(0,j).concat(outkeyarray.slice(j+1,outkeyarray.length))

outtfxarray = outtfxarray.slice(0,j).concat(outtfxarray.slice(j+1,outtfxarray.length))

}
}
}
outtags.value = outkeyarray.join("
,"
)

}
<
/script>