Alpha Space Validation in JS

Enter text file allow allphabi & space only
function alpha_space_validation(arg){
 var valReg = /^[A-Za-z ]+$/;
 if(valReg.test( arg ) ) {
  return false;
 } else {
  return true;
 }
}

Email Validation - Form field Validate Email Address

alert(email_validation("asasas"))
function email_validation(arg){
 var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
 if( !emailReg.test( arg ) ) {
  return false;
 } else {
  return true;
 }
}

PHP number format 4 digits [duplicate]

Method I

echo str_pad( "3", 4, "0", STR_PAD_LEFT );
Input $s_number = "3"; Output: 0003

Method II

$s_number = '12';
printf("%04d", $s_number);
Input $s_number = "12"; Output: 0012