日期:2012-01-15  浏览次数:20900 次

    正则表达式的用途很广泛,但要熟练掌握就不是一件容易的事情了。为此,我编写了这个练习器用来帮助学习。
    请多指教!

*********将以下代码复制到 RegExp.htm 即可 **********
<HTML>
<HEAD>
<TITLE>正则表达式练习器</TITLE>
<meta name = 安徽 池州 统计局 徐祖宁 e-mail:czjsz@stats.gov.cn>
<script language="JavaScript">
function OnMove() {
window.status = "("+window.event.clientX+","+window.event.clientY+")" + " :: "+document.location
}
</script>

<SCRIPT LANGUAGE="JavaScript1.2">
var re = new RegExp()  //建立正则表达式对象
var nextpoint = 0      //匹配时的偏移量
//设置正则表达式
function setPattern(form) {
  var mode
  if(form.chkmode.checked) mode = "gi"  //i:不分大小写 g:全局,好象没什么作用
  else mode = "g"
  re.compile(form.regexp.value,mode)
  nextpoint = 0
  form.reglist.value = ""
}
//检查是否有匹配
function findIt(form) {
  setPattern(form)
  var input = form.main.value
  if (input.search(re) != -1) {
    form.output[0].checked = true    
  } else {
    form.output[1].checked = true    
  }
}
//检查匹配位置
function locateIt(form) {
  setPattern(form)
  var input = form.main.value
  form.offset.value = input.search(re)
}
//检查所有的匹配情况
function execIt(form) {
  if(nextpoint == 0 || ! form.scankmode.checked) {
    findIt(form)
    form.reglist.value = ""
  }
  var key = true
  if(form.scankmode.checked) key = false
  do {
    var input = form.main.value
    var matchArray = re.exec(input.substr(nextpoint))
    if(matchArray) {
      for(var i=1;i<matchArray.length;i++)
        matchArray[i] = "$"+i+":"+matchArray[i]
      form.reglist.value = (nextpoint+matchArray.index)+" => " + matchArray[0] +"\n"+form.reglist.value
      form.matchlist.value = "$0:"+matchArray.join("\n")
      nextpoint = nextpoint + matchArray.index + matchArray[0].length
    }else {
      if(!key)
        form.reglist.value = "没有找到\n" + form.reglist.value
      form.matchlist.value = " "
      nextpoint = 0
      key = false
    }
  }while (key)
}
//设置当前使用的正则表达式
function setregexp(n) {
  var s = document.all.regexplist.value.split("\r\n")
  document.all.regexp.value = s[n*2-1]  //.replace("\r","")
  nextpoint = 0
}

//定义选择监视
var isNav = (navigator.appName == "Netscape")
function showSelection() {
  if (isNav) {
    var theText = document.getSelection()
  } else {
    var theText = document.selection.createRange().text
  }
  if(theText.length>0 && document.all.selechkmode.checked)
    document.all.regexp.value = theText
}
if (isNav) {
    document.captureEvents(Event.MOUSEUP)
}
doc