JS restrictions: only numbers can be input, case-insensitive conversion, and length restrictions

Only numbers can be entered

Function nonumbers (OBJ)
{
OBJ. value = obj. value. Replace (/[^ \ D.]/g ,"");
OBJ. value = obj. value. Replace (/^ \./g ,"");
OBJ. value = obj. value. Replace (/\. {2,}/g ,".");
OBJ. value = obj. value. replace (". "," $ # $ "). replace (/\. /g ,""). replace ("$ # $ ",". ");

}

Call:

<Input type = "text" onkeyup = "Return nonumbers (this)" ondragenter = "Return false"
Style = "ime-mode: Disabled"
>

 

Ondragenter = "Return false": Do not drag in content

Style = "ime-mode: Disabled": the input method is forbidden.

 

 

Convert to uppercase:

Function touppercase (id_name ){
VaR nkeycode = Window. event. keycode;
If (nkeycode! = 37 & nkeycode! = 39 & nkeycode! = 8)
{
VaR OBJ = Document. getelementbyid (id_name)
VaR Pos = getpos (OBJ); // obtain the cursor position
Uppercase (OBJ); // converts lowercase letters to uppercase letters.
Setpos (OBJ, POS); // you can specify the cursor position.
}
}

Call:

<Input type = "text" name = "Cyc 'onkeypress =" touppercase ('cyc'); ">

 

Length limit:

Function checklength (OBJ, Len ){
VaR STR = obj. value;
If (Str. length> Len ){
Alert ("the input length cannot exceed:" + Len );
OBJ. value = Str. substring (0, 4 );
OBJ. Focus ();
Return;
}
}

 

Call:

<Input type = "text" name = "Cyc 'onkeypress =" checklength (this, 4 );"