validations.js

//designing code for data validations

//const f=document.forms[0];  or
const frm=document.querySelector("#frm1");

/*attach Event
frm.onsubmit=function(){
	
	code
	
}  or */
frm.addEventListener("Submit",checkData);


//data validation
function checkData(f)//this method returns form tag Object 
{
	
	//fullname checking
	const fnaa=document.querySelector("#fna").value;
	const fnaaexp=/^[a-zA-Z]*$/;
	
	if(fnaaexp.test(fnaa)===false || fna==="")
	{
		document.querySelector("#errfna").innerHTML=`plz enter valid name`;
		f.preventDefault();//browser dont submit my form
	}
	else{
		document.querySelector("#errfna").innerHTML="";
	}
	
	//phone num checking
	const ph=document.querySelector("#phone").value;
	const phexp=/^[6-9]\d{9} $/;  //[6-9]->starting first digit b/w 6 to 9 and \d{9}->remaining 9 digits any digits
	if(phexp.test(ph)===false)
	{
		document.querySelector("#errph").innerHTML=`enter a valid phone number`;
		f.preventDefault();
	}else{
		document.querySelector("#errph").innerHTML="";
	}
	
	//pincode checking
	const pc=document.querySelector("#pin").value;
	const pcexp=/^\d{6} $/;  
	if(pcexp.test(pc)===false)
	{
		document.querySelector("#errpc").innerHTML=`enter a valid pin code`;
		f.preventDefault();
	}else{
		document.querySelector("#errpc").innerHTML="";
	}
	
	//Password checking
	const pw=document.querySelector("#pwd").value;
	const pwexp=/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@#$%&*]).{8,20}$/;  
	if(pcexp.test(pw)===false)
	{
		document.querySelector("#errpwd").innerHTML=`Password should contains atleast 1 lower,upper, digits & symbol`;
		f.preventDefault();
	}else{
		document.querySelector("#errpwd").innerHTML="";
	}

}