Summary: some nice JS functions that are frequently used

Make the following Javascript file and call it on any page.
/* = =
* 1. var_to_obj --------- convert a variable to an object
* 2. is_greater --------- determine whether the number is greater than a certain number
* 3. is_less ---------- determine whether it is smaller than a certain number
* 4. compare_date ------ compare the sizes of two dates. num1> num2 return: true; num1 <= num2 return: false
* 5. is_numeric ------ determine if it is a number
* 6. is_price ----- determine whether it is in the price format: 00.00 with two decimal places
* 7. is_null ----- determines whether it is null. True: NULL. False: not empty.
* 8. isspace ------ determines whether it is a space.
* 9. isspace ---- determines whether it is a space.
* 10. is_int (---- judge whether the integer is true: Yes integer, false: Not integer
* 11. is_date ---- determine whether it is a date
* 12. is_date2 --- determine whether it is a date
* 13. isselected ---- determine whether valid data is selected
* 14. ischaracter ---- check whether it is a character
* 15. isothernamecharacter ----- check whether there are other characters that can be named
* 16. isnamecharacter ----- check whether the character can be named
* 17. isemail ----- check whether it is email
* 18. iszip ---- check for zip code
* 19. isdigitalstring ----- check whether it is a numeric string
* 20. isempty ----- The isempty function checks whether a string is null.
* 21. Trim ----- the trim function removes spaces on both sides of a string.
* 22. isdigital-The isdigital function determines whether a string is composed of digits (Int or long ).
* 23. isfloat ---- The isfloat function determines whether a string is composed of digits (Int or long or float ).
* 24. istelephone --- determines whether a string is composed of digits, '-', '*', and '()'.
* 25. datetransfer ----- date format conversion 2/18/2000 ---- 2000-2-18
* 26. transferdate ---- conversion date 2000-10-20 ----> 10/20/2000
* 27. ispassword ----- check whether the password is used
* 28. isleapyear ----- determines whether it is a function of the runyear.
* 29. getdaysinmonth ---- function for obtaining the number of days per month
* 30. jtrimstr --- Remove all spaces in the string
* ===================================================== ======= */

Function doinputconnotempty (txtinput, minlength, salert ){
Txtinput. value = trim (txtinput. value );
VaR m_isvalid = true;
If (isempty (txtinput. Value) m_isvalid = false;
If (minlength> 0 ){
If (txtinput. value. Length <minlength) m_isvalid = false;
}
If (! M_isvalid ){
If (salert! = "") Window. Alert (salert );
Txtinput. Focus ();
}
Return m_isvalid;
}

// convert a variable to an object
function var_to_obj (VAL)
{< br> This. value = val;
}< br> // determines whether the value is greater than a certain number.
function is_greater (field, crit, limit)
{< br> var ret = (is_numeric (field,-1 ))? (Field. value> limit): false;
If (! RET)
docritcode (field, crit, "value must be greater than" + limit);
return (RET );
}< br> // determines whether the value is smaller than a certain number.
function is_less (field, crit, limit)
{< br> var ret = (is_numeric (field,-1 ))? (Field. value If (! RET)
docritcode (field, crit, "value must be less than" + limit);
return (RET);
}

function is_numeric (field, crit, MSG)
{< br> var ret = true;
var numstr = "0123456789 ";
var decused = false;
var CHR;
for (I = 0; I {< br> CHR = field. value. charat (I);
If (numstr. indexof (CHR, 0) =-1)
{< br> If ((! Decused) & CHR = ". ")
{< br> decused = true;
}< br> else
{< br> ret = false;
}< BR >}< br> If (! RET)
docritcode (field, crit, MSG);
return (RET );
}< br> // determine whether it is a price
function is_price (field, crit, MSG)
{< br> var ret = true;
var numstr = "0123456789";
var decused = false;
var CHR;
for (I = 0; I {< br> CHR = field. value. charat (I);
If (numstr. indexof (CHR, 0) =-1)
{< br> If ((! Decused) & CHR = ". ")
{< br> decused = true;
}< br> else
{< br> ret = false;
}< BR >}< br> If (RET)
{< br> If (decused & (field. value. length-field.value.indexOf ('. ') <4)
;< br> else if (decused)
ret = false;
}< br> If (! RET)
docritcode (field, crit, MSG);
return (RET);
}

// determine whether it is null
function is_null (field, crit, MSG)
{< br> var text = "" + trim (field. value);
If (text. length)
{for (VAR I = 0; I If (text. charat (I )! = "" & Text. charat (I )! = "")
break;
if (I> = text. length) {
ret = true;}
else {
ret = false;}
}< br> else
ret = true;
If (RET)
docritcode (field, crit, MSG);
return (RET);
}< br> function isspace (field)
{< br> var text = "" + field. value;
If (text. length)
{< br> for (VAR I = 0; I If (text. charat (I )! = "" & Text. charat (I )! = "")
break;
if (I> = text. length)
field. value = "";
}< BR >}

function docritcode (field, crit, MSG)
{< br> If (-1! = Crit)
{< br> alert (MSG)
If (CRIT = 1)
{< br> field. focus (); // focus does not work on certain Netscape versions
field. select ();
}< BR >}< br> // determines whether it is an integer
function is_int (field, crit, MSG) {
var ret = true;
var numstr = "0123456789";
var CHR;
If (field. value. length = 0)
{< br> ret = false;
}< br> for (I = 0; I {< br> CHR = field. value. charat (I);
If (numst R. indexof (CHR, 0) =-1)
{< br> ret = false;
}< BR >}< br> If (! RET)
docritcode (field, crit, MSG);
return (RET );
}< br> // determines whether it is a date
function is_date (field, crit, MSG) {
var ret = false;
var mark1;
var mark2;
var days;
var y;
var m;
var D;
If (field. value = "")
return true;
Cd = new date ();

If (mark1 = field. value. indexof ('-') =-1)
Mark1 = field. value. indexof ('-')
If (mark1>-1)
{
If (mark2 = field. value. indexof ('-', mark1 + 1) =-1)
Mark2 = field. value. indexof ('-', mark1 + 1 );
If (mark2>-1) & (mark2 + 1 <field. value. Length ))
{
Y = parseint (field. value. substring (0, mark1), 10 );
M = parseint (field. value. substring (mark1 + 1, mark2), 10 );
D = parseint (field. value. substring (mark2 + 1, field. value. length), 10 );

Year = new var_to_obj (y );
Month = new var_to_obj (m );
Day = new var_to_obj (d );
Days = getdaysinmonth (month. Value, year. Value) + 1;

If (
(Is_greater (day,-1, 0) & (is_less (day,-1, days ))&&
(Is_greater (month,-) & (is_less (month ))&&
(Is_greater (year,-) & (is_less (year ))
)
Ret = true;
}
}
If (! RET) docritcode (field, crit, MSG );

Return (RET );
}

Function docrit (field, crit, MSG)
{
If (-1! = Crit ))
{
Alert (MSG );
If (CRIT = 1)
{
Field. Focus (); // focus does not work on certain Netscape versions
}
}
}
// Determine whether valid data is selected
Function isselected (field, crit, MSG)
{
Value = "" + field. Options [field. selectedindex]. value;
If (value = "0 ")
Ret = false;
Else
Ret = true;
If (! RET)
Docrit (field, crit, MSG );
Return (RET );
}

// Check whether it is a character
// Ccharacter: input value
Function ischaracter (ccharacter)
{
VaR sformat = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz ";

If (sformat. indexof (ccharacter, 0) =-1)
{
Return false;
}

Return true;
}

// Determine whether it is a combination of numbers and letters
Function ischrandnum (ccharacter)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
If (Str. charat (ilen) <'A' | Str. charat (ilen)> 'Z ')
{
If (Str. charat (ilen) <'A' | Str. charat (ilen)> 'Z ')
Return false;
}
}
}
Return true;
}

// Check whether there are other characters that can be named
// Ccharacter: input value
Function isothernamecharacter (ccharacter)
{
VaR sformat = "_";

If (sformat. indexof (ccharacter, 0) =-1)
{
Return false;
}

Return true;
}
Function isothernamecharacter1 (ccharacter)
{
VaR sformat = "-";

If (sformat. indexof (ccharacter, 0) =-1)
{
Return false;
}

Return true;
}

Function isothernamecharacter2 (ccharacter)
{
VaR sformat = ".";

If (sformat. indexof (ccharacter, 0) =-1)
{
Return false;
}

Return true;
}

// Check whether the name can be a character
// Svalue: input value
Function isnamecharacter (svalue)
{
If (svalue = NULL)
{
Return false;
}

For (I = 0; I <svalue. length; I ++)
{
VaR ccharacter = svalue. charat (I );
If (isdigital (ccharacter) = false & ischaracter (ccharacter) = false & isothernamecharacter (ccharacter) = false & isothernamecharacter1 (ccharacter) = false & isothernamecharacter2 (ccharacter) = false)
{
Return false;
}
}

Return true;
}
// Check whether the password is used
Function ispassword (svalue)
{
If (svalue = NULL)
{
Return false;
}

For (I = 0; I <svalue. length; I ++)
{
VaR ccharacter = svalue. charat (I );
If (isdigital (ccharacter) = false & ischaracter (ccharacter) = false & isothernamecharacter (ccharacter) = false)
{
Return false;
}
}

Return true;
}

// Check whether it is email
// Svalue: input value. Valid format: a@ B .c.d.
Function isemail (svalue)
{
VaR ifirstindex = 0;
VaR isecondindex = svalue. indexof ('@');
If (isecondindex =-1)
{
Return false;
}

VaR stemp = svalue. substring (ifirstindex, isecondindex );
If (isnamecharacter (stemp) = false)
{
Return false;
}

Isecondindex = svalue. indexof ('.');
If (isecondindex =-1 | svalue. substring (svalue. Length-1, svalue. Length) = '.')
{
Return false;
}
Else if (stemp. Length = svalue. Length-2) // The last two characters are '@' and '.'
{
Return false;
}
Else
{
VaR stempvalue = svalue;
Isecondindex = svalue. indexof ('@');
While (isecondindex! =-1)
{
Ifirstindex = isecondindex + 1;
Stempvalue = stempvalue. substring (ifirstindex, stempvalue. Length); // The right section of Value
Isecondindex = stempvalue. indexof ('.');
// Document. Write ("stempvalue =" + stempvalue + "<br> ");
Stemp = stempvalue. substring (0, isecondindex );
// Document. Write ("stemp =" + stemp + "<br> ");
If (isnamecharacter (stemp) = false)
{
Return false;
}
}

If (isnamecharacter (stempvalue) = false)
{
Return false;
}
}

Return true;
}

// Check for zip code
// Svalue: the input value. The valid format is a six-digit integer.
Function iszip (svalue)
{
If (svalue = NULL)
{
Return false;
}

If (svalue. length! = 6)
{
Return false;
}
Else
{
For (I = 0; I <6; I ++)
{
If (isdigital (svalue. charat (I) = false)
{
Return false;
}
}
}

Return true;
}

// Check whether the string is a numeric string
// Svalue: input value
Function isdigitalstring (svalue)
{
If (svalue = NULL)
{
Return false;
}

For (I = 0; I <svalue. length; I ++)
{
If (isdigital (svalue. charat (I) = false)
{
Return false;
}
}
}

// The isempty function checks whether a string is null.
Function isempty (HIS)
{
Flag = true;
For (VAR I = 0; I {
If (his. charat (I )! = "")
{
Flag = false;
Break;
}
}
Return flag;
}
// Remove spaces on both sides of a string from the trim Function
Function trim (HIS)
{
// Locate the start position of the string
Pos_start =-1;
For (VAR I = 0; I {
If (his. charat (I )! = "")
{
Pos_start = I;
Break;
}
}
// Locate the end position of the string
Pos_end =-1;
For (VAR I = His. Length-1; I> = 0; I --)
{
If (his. charat (I )! = "")
{
Pos_end = I;
Break;
}
}
// Return string
Str_return = ""
If (pos_start! =-1 & pos_end! =-1)
{
For (VAR I = pos_start; I <= pos_end; I ++)
{
Str_return = str_return + his. charat (I );
}
}
Return str_return;
}
// The isdigital function determines whether a string is composed of digits (Int or long ).
Function isdigital (STR)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
Return false;
}
}
Return true;
}
// The isfloat function determines whether a string is composed of digits (Int or long or float ).
Function isfloat (STR)
{
Flag_dec = 0
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) = '.')
{
Flag_dec ++;
If (flag_dec> 1)
Return false;
Else
Continue;
}
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
Return false;
}
}
Return true;
}
// The istelephone function determines whether a string is composed of numbers, '-', and '*'.
Function istelephone (STR)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
If (Str. charat (ilen )! = '-') & (Str. charat (ilen )! = '*'))
Return false;
}
}
Return true;
}

// Compare the values of two dates, num1> num2 return: true; num1 <= num2 return: false
Function compare_date (num1, num2)
{
VaR pos1, pos2, end;
VaR para1, para2, para3, para4, para5, para6;

// para1: year
// para2: month
// para3: day
end = num1.length;
pos1 = num1.indexof ("-", 0);
pos2 = num1.indexof ("-", pos1 + 1);
para1 = num1.substring (0, pos1);
para2 = num1.substring (pos1 + 1, pos2);
para3 = num1.substring (pos2 + 1, end);
para1 = parseint (para1, 10);
para2 = parseint (para2, 10);
para3 = parseint (para3, 10);
end = num2.length;
pos1 = num2.indexof ("-", 0);
pos2 = num2.indexof ("-", pos1 + 1);
para4 = num2.substring (0, pos1);
para5 = num2.substring (pos1 + 1, pos2);
para6 = num2.substring (pos2 + 1, end);
para4 = parseint (para4, 10);
para5 = parseint (para5, 10);
para6 = parseint (para6, 10);
If (para1> para4)
{< br> return true;
}< br> else if (para1 = para4)
{< br> If (para2> para5)
{< br> return true;
}< br> else if (para2 = para5)
{< br> If (para3> para6)
{< br> return true;
}< BR >}l. co
return false;
}

// remove all spaces in the string
function jtrimstr (STR)
{< br> var I = 0;
var J;
var Len = Str. length;
trimstr = "";
while (I {< br> If (Str. charat (I )! = "")
{< br> trimstr = trimstr + Str. charat (I);
}< br> I ++;
}< br> return (trimstr );
}< br> // conversion date
function transferdate (STR)
{< br> var M = 4;
var strlen = Str. length
var n = strlen-1;
while (n> = strlen-2)
{
If (Str. charat (n) = "-")
{< br> break;
}< br> N = n-1
}< br> trimstr = Str. substring (m + 1, n) + "/" + Str. substring (n + 1, strlen) + "/" + Str. substring (0, m)
return (trimstr)
}

// 1. Obtain the function of the number of days per month
// Parameter description: month-month; year-year
// Return value: days -- days
Function getdaysinmonth (month, year ){
VaR days;
If (month = 1 | month = 3 | month = 5 | month = 7 | month = 8 | month = 10 | month = = 12) days = 31;
Else if (month = 4 | month = 6 | month = 9 | month = 11) days = 30;
Else if (month = 2 ){
If (isleapyear (year) {days = 29 ;}
Else {days = 28 ;}
}
Return (days );
}
// 2. Determine whether the function is a runyear Function
// Parameter description: year -- year
// Return value: True is returned if it is a runyear; otherwise, false is returned.

Function isleapyear (year ){
If (Year % 4) = 0) & (Year % 100 )! = 0) | (Year % 400) = 0 )){
Return (true );
} Else {return (false );}
}

Function ischarnum (STR)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
If (Str. charat (ilen )! = 'X '))
Return false;
}
}
Return true;
}

Function ischarsf (STR)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
If (Str. charat (ilen) <'A' | Str. charat (ilen)> 'Z ')
Return false;
}
}
Return true;
}

// Determine whether a string is composed of numbers and "-"

Function ismonth (STR)
{
For (ilen = 0; ilen <Str. length; ilen ++)
{
If (Str. charat (ilen) <'0' | Str. charat (ilen)> '9 ')
{
If (Str. charat (ilen )! = '-'))
Return false;
}
}
Return true;
}

// Dialog box
Function popmodaldialog (URL, argS, height, width ){
Return window. showmodaldialog (URL, argS, "dialogheight:" + height + "PX; dialogwidth:" + width + "PX; center: Yes; help: No; resizable: No; Status: no ;");
}