JavaScript正则表达式校验与递归函数实际应用实例解析

　JS递归函数（菲波那切数列）

实例解析： 

一组数字:0 1 1 2 3 5 8 13
        0 1 2 3 4 5 6 7
　　sl(0)=0;
　　sl(1)=1;
　　sl(2)=sl(0)+sl(1);
　　sl(3)=sl(1)+sl(2);
　　function sl(i){
　　　　if(i==0){
　　　　　return 0;
}else if(i==1){
　　　　　return 1;
}else{
　　　　　return sl(i-1)+sl(i-2);
}
}

　　正则表达式检验

//校验是否全由数字组成
function isDigit(s)
{
var patrn=/^[0-9]{1,20}$/;
if (!patrn.exec(s)) return false
return true
}
//校验登录名：只能输入5-20个以字母开头、可带数字、“_”、“.”的字串
function isRegisterUserName(s)
{
var patrn=/^[a-zA-Z]{1}([a-zA-Z0-9]|[._]){4,19}$/;
if (!patrn.exec(s)) return false
return true
}
//校验用户姓名：只能输入1-30个以字母开头的字串
function isTrueName(s)
{
var patrn=/^[a-zA-Z]{1,30}$/;
if (!patrn.exec(s)) return false
return true
}
//校验密码：只能输入6-20个字母、数字、下划线
function isPasswd(s)
{
var patrn=/^(\w){6,20}$/;
if (!patrn.exec(s)) return false
return true
}
//校验普通电话、传真号码：可以“+”开头，除数字外，可含有“-”
function isTel(s)
{
//var patrn=/^[+]{0,1}(\d){1,3}[ ]?([-]?(\d){1,12})+$/;
var patrn=/^[+]{0,1}(\d){1,3}[ ]?([-]?((\d)|[ ]){1,12})+$/;
if (!patrn.exec(s)) return false
return true
}
//校验手机号码：必须以数字开头，除数字外，可含有“-”
function isMobil(s)
{
var patrn=/^[+]{0,1}(\d){1,3}[ ]?([-]?((\d)|[ ]){1,12})+$/;
if (!patrn.exec(s)) return false
return true
}
//校验邮政编码
function isPostalCode(s)
{
//var patrn=/^[a-zA-Z0-9]{3,12}$/;
var patrn=/^[a-zA-Z0-9 ]{3,12}$/;
if (!patrn.exec(s)) return false
return true
}
//校验搜索关键字
function isSearch(s)
{
var patrn=/^[^`~!@#$%^&*()+=|\\\][\]\{\}:;\'\,.<>/?]{1}[^`~!@$%^&()+=|\\\][\]\{\}:;\'\,.<>?]{0,19}$/;
if (!patrn.exec(s)) return false
return true
}
function isIP(s) //by zergling
{
var patrn=/^[0-9.]{1,20}$/;
if (!patrn.exec(s)) return false
return true
}
* FUNCTION: isBetween
* PARAMETERS: val AS any value
* lo AS Lower limit to check
* hi AS Higher limit to check
* CALLS: NOTHING
* RETURNS: TRUE if val is between lo and hi both inclusive, otherwise false.
function isBetween (val, lo, hi) {
if ((val < lo) || (val > hi)) { return(false); }
else { return(true); }
}
* FUNCTION: isDate checks a valid date
* PARAMETERS: theStr AS String
* CALLS: isBetween, isInt
* RETURNS: TRUE if theStr is a valid date otherwise false.
function isDate (theStr) {
var the1st = theStr.indexOf('-');
var the2nd = theStr.lastIndexOf('-');
if (the1st == the2nd) { return(false); }
else {
var y = theStr.substring(0,the1st);
var m = theStr.substring(the1st+1,the2nd);
var d = theStr.substring(the2nd+1,theStr.length);
var maxDays = 31;
if (isInt(m)==false || isInt(d)==false || isInt(y)==false) {
return(false); }
else if (y.length < 4) { return(false); }
else if (!isBetween (m, 1, 12)) { return(false); }
else if (m==4 || m==6 || m==9 || m==11) maxDays = 30;
else if (m==2) {
if (y % 4 > 0) maxDays = 28;
else if (y % 100 == 0 && y % 400 > 0) maxDays = 28;
else maxDays = 29;
}
if (isBetween(d, 1, maxDays) == false) { return(false); }
else { return(true); }
}
}
* FUNCTION: isEuDate checks a valid date in British format
* PARAMETERS: theStr AS String
* CALLS: isBetween, isInt
* RETURNS: TRUE if theStr is a valid date otherwise false.
function isEuDate (theStr) {
if (isBetween(theStr.length, 8, 10) == false) { return(false); }
else {
var the1st = theStr.indexOf('/');
var the2nd = theStr.lastIndexOf('/');
if (the1st == the2nd) { return(false); }
else {
var m = theStr.substring(the1st+1,the2nd);
var d = theStr.substring(0,the1st);
var y = theStr.substring(the2nd+1,theStr.length);
var maxDays = 31;
if (isInt(m)==false || isInt(d)==false || isInt(y)==false) {
return(false); }
else if (y.length < 4) { return(false); }
else if (isBetween (m, 1, 12) == false) { return(false); }
else if (m==4 || m==6 || m==9 || m==11) maxDays = 30;
else if (m==2) {
if (y % 4 > 0) maxDays = 28;
else if (y % 100 == 0 && y % 400 > 0) maxDays = 28;
else maxDays = 29;
}
if (isBetween(d, 1, maxDays) == false) { return(false); }
else { return(true); }
}
}
}
* FUNCTION: Compare Date! Which is the latest!
* PARAMETERS: lessDate,moreDate AS String
* CALLS: isDate,isBetween
* RETURNS: TRUE if lessDateDate2) { return(false);}
return(true);
}
* FUNCTION isEmpty checks if the parameter is empty or null
* PARAMETER str AS String
function isEmpty (str) {
if ((str==null)||(str.length==0)) return true;
else return(false);
}
* FUNCTION: isInt
* PARAMETER: theStr AS String
* RETURNS: TRUE if the passed parameter is an integer, otherwise FALSE
* CALLS: isDigit
function isInt (theStr) {
var flag = true;
if (isEmpty(theStr)) { flag=false; }
else
{ for (var i=0; i decLen) return(false);
else if (!isInt(intPart) || !isInt(decPart)) return (false);
else if (isEmpty(decPart)) return (false);
else return(true);
}
}
* FUNCTION: isEmail
* PARAMETER: String (Email Address)
* RETURNS: TRUE if the String is a valid Email address
* FALSE if the passed string is not a valid Email Address
* EMAIL FORMAT: AnyName@EmailServer e.g; [email protected]
* @ sign can appear only once in the email address.
function isEmail (theStr) {
var atIndex = theStr.indexOf('@');
var dotIndex = theStr.indexOf('.', atIndex);
var flag = true;
theSub = theStr.substring(0, dotIndex+1)
if ((atIndex < 1)||(atIndex != theStr.lastIndexOf('@'))||(dotIndex < atIndex + 2)||(theStr.length <= theSub.length))
{ return(false); }
else { return(true); }
}
* FUNCTION: newWindow
* PARAMETERS: doc -> Document to open in the new window
hite -> Height of the new window
wide -> Width of the new window
bars -> 1-Scroll bars = YES 0-Scroll Bars = NO
resize -> 1-Resizable = YES 0-Resizable = NO
* CALLS: NONE
* RETURNS: New window instance
function newWindow (doc, hite, wide, bars, resize) {
var winNew="_blank";
var opt="toolbar=0,location=0,directories=0,status=0,menubar=0,";
opt+=("scrollbars="+bars+",");
opt+=("resizable="+resize+",");
opt+=("width="+wide+",");
opt+=("height="+hite);
winHandle=window.open(doc,winNew,opt);
return;
}
* FUNCTION: DecimalFormat
* PARAMETERS: paramValue -> Field value
* CALLS: NONE
* RETURNS: Formated string
function DecimalFormat (paramValue) {
var intPart = parseInt(paramValue);
var decPart =parseFloat(paramValue) - intPart;
str = "";
if ((decPart == 0) || (decPart == null)) str += (intPart + ".00");
else str += (intPart + decPart);
return (str);
}

正则表达式应用

"^\\d+$"　　//非负整数（正整数 + 0） 
"^[0-9]*[1-9][0-9]*$"　　//正整数 
"^((-\\d+)|(0+))$"　　//非正整数（负整数 + 0） 
"^-[0-9]*[1-9][0-9]*$"　　//负整数 
"^-?\\d+$"　　　　//整数 
"^\\d+(\\.\\d+)?$"　　//非负浮点数（正浮点数 + 0） 
"^(([0-9]+\\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\\.[0-9]+)|([0-9]*[1-9][0-9]*))$"　　//正浮点数 
"^((-\\d+(\\.\\d+)?)|(0+(\\.0+)?))$"　　//非正浮点数（负浮点数 + 0） 
"^(-(([0-9]+\\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\\.[0-9]+)|([0-9]*[1-9][0-9]*)))$"　　//负浮点数 
"^(-?\\d+)(\\.\\d+)?$"　　//浮点数 
"^[A-Za-z]+$"　　//由26个英文字母组成的字符串 
"^[A-Z]+$"　　//由26个英文字母的大写组成的字符串 
"^[a-z]+$"　　//由26个英文字母的小写组成的字符串 
"^[A-Za-z0-9]+$"　　//由数字和26个英文字母组成的字符串 
"^\\w+$"　　//由数字、26个英文字母或者下划线组成的字符串 
"^[\\w-]+(\\.[\\w-]+)*@[\\w-]+(\\.[\\w-]+)+$"　　　　//email地址 
"^[a-zA-z]+://(\\w+(-\\w+)*)(\\.(\\w+(-\\w+)*))*(\\?\\S*)?$"　　//url

递归函数应用

总结

以上所述是小编给大家介绍的JavaScript正则表达式校验与递归函数实际应用实例解析，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！