JavaScript Tutorial: A function used to determine whether a date is correct

The IsDate function of VBScript is used to determine whether a date is correct. If JavaScript does not have this function, we will also write a similar function. It must be noted that the IsDate parameter in JavaScript must be a string, six different formats are supported: "yyyy-mm-dd | yyyy/mm/dd | dd-mm-yyyy | dd/mm/yyyy | mm-dd- yyyy | mm/dd/yyyy ", the reason why Date cannot be used as a parameter is that JavaScript does not have an incorrect Date, such as new Date (, 30 ), the constructor will automatically convert it to the correct date 2008-03-01. The IsDate function for JavaScript is as follows:

Function IsDate (dateval ){
Var arr = new Array ();

If (dateval. indexOf ("-")! =-1 ){
Arr = dateval. toString (). split ("-");
} Else if (dateval. indexOf ("/")! =-1 ){
Arr = dateval. toString (). split ("/");
} Else {
Return false;
}

// Yyyy-mm-dd | yyyy/mm/dd
If (arr [0]. length = 4 ){
Var date = new Date (arr [0], arr [1]-1, arr [2]);
If (date. getFullYear () = arr [0] & date. getMonth () = arr [1]-1 & date. getDate () = arr [2]) {
Return true;
}

 

}
// Dd-mm-yyyy | dd/mm/yyyy
If (arr [2]. length = 4 ){
Var date = new Date (arr [2], arr [1]-1, arr [0]);
If (date. getFullYear () = arr [2] & date. getMonth () = arr [1]-1 & date. getDate () = arr [0]) {
Return true;
}
}
// Mm-dd-yyyy | mm/dd/yyyy
If (arr [2]. length = 4 ){
Var date = new Date (arr [2], arr [0]-1, arr [1]);
If (date. getFullYear () = arr [2] & date. getMonth () = arr [0]-1 & date. getDate () = arr [1]) {
Return true;
}
} Webpage teaching network

Return false;
}