html>
  script language="javascript">
    //var pattern = /[^"]*/;  //校驗(yàn)字符串中是否都是非雙引號的字符
    var pattern = /["]+/;    //校驗(yàn)字符串中是否有雙引號的字符
    //var pattern = /["][^"]*["]/  //匹配的是位于單引號或者雙引號之內(nèi)的0個(gè)或多個(gè)字符
    var value1 = "The best things in life are free";  //沒有雙引號的字符串
    var value2 = "/"/"The /"best things /"in life are free/"/"";  //有雙引號的字符串
    alert("value1沒有雙引號的字符串 pattern.exec_1===" + pattern.exec(value1));  //null
    alert("value1沒有雙引號的字符串 !pattern.exec_2===" + !pattern.exec(value1));  //true
    alert("value2有雙引號的字符串 pattern.exec_1===" + pattern.exec(value2));  //""
    alert("value2有雙引號的字符串 !pattern.exec_2===" + !pattern.exec(value2));  //false 
    if(pattern.exec(value1)){  //校驗(yàn)字符串中是否都是非雙引號的字符
      alert("value1 沒有加非號 ++++++雙引號被匹配上");
    }
    if(!pattern.exec(value1)){    //校驗(yàn)字符串中是否有雙引號的字符
      alert("value1 有加非號 ++++++雙引號被匹配上");  //頁面窗口彈出
    }
    if(pattern.exec(value2)){  //校驗(yàn)字符串中是否都是非雙引號的字符
      alert("value2 沒有加非號 ++++++雙引號被匹配上");  //頁面窗口彈出
    }
    if(!pattern.exec(value2)){    //校驗(yàn)字符串中是否有雙引號的字符
      alert("value2 有加非號 ++++++雙引號被匹配上");
    }
    /script>
/html>