Creating an if statement that validates whether all variables have non-null values

I am still getting the hang of javascript and working on some coding projects from my textbooks. The current task involves creating an if statement to check if the values of the elements referenced by the names fname, lname, and zip are all not null.

Here is the script I have written so far:

var newAccountArray = [];

function createID() {
var fname = fnameinput;
var lname = lnameinput;
var zip = zipinput;
var account = accountidbox
var fields = input;
var acctid;
var firstInit;
var lastInit;

if ( !== null)



}

I'm curious about whether I need to approach multiple variables differently in this case.

Should I use if (myVar) or if (myVar !== null)

Answer №1

One way to handle this situation is as follows:

if(firstName && lastName && zipCode){
   // your custom code here
}

This conditional statement ensures that firstName, lastName, and zipCode are not falsy values (null, undefined, "", false, 0, or NaN).

Answer №2

Rohitas Behera points out in the comments that simply using if(variable) is sufficient.

The condition if(variable) will not be met when variable is null, undefined, false (boolean value), or an empty string.

An issue with using if(variable) is that sometimes you need the if statement to pass even if the variable is an empty string, which can be a legitimate case. In such situations, you can use the following:

if(variable || variable === '')

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