When I push an object in array it remains empty

Question

Whenever my form is submitted nothing happens and when I check my array on the console it remains empty. In order to target values of input I need to put it in a function I also use return in function but nothing happens. Actually I want user data collected in object and push into array whenever I click on submit button...

var labelsarray = document.getElementsByTagName("label");
var inputsarray = document.getElementsByTagName("input");
var array = [];
function subm() {
    var users = {
        FirstName: inputsarray[0].value,
        LastName: inputsarray[1].value,
        UserName: inputsarray[2].value,
        Password:  inputsarray[3].value,
        DateofBirth: inputsarray[4].value,
        Age: inputsarray[5].value,
        Gender: inputsarray[6, 7].checked,
        Purpose: inputsarray[8, 9, 10].checked
    };
    array.push(users);
}

<div>
    <center>
        <form method="post" onsubmit="subm();">
            <label for="fname">First Name:</label>&emsp;
            <input type="text" id="fname" />
            <br/>
            <label for="lname">Last Name:</label>&emsp;
            <input type="text" id="lname" />
            <br/>
            <label for="uname">User Name:</label>&emsp;
            <input type="text" id="uname" />
            <br/>
            <label for="pass">Password:</label>&emsp;&ensp;&nbsp;
            <input type="text" id="pass" />
            <br/>
            <label for="dob">Date of Birth:</label>&emsp;&emsp;&nbsp;
            <input type="date" id="dob" />
            <br/>
            <label>Age:</label>&emsp;&emsp;&emsp;&emsp;&emsp;
            <input type="text" id="age" />
            <br/>
            <span>Gender:</span>&emsp;&emsp;&emsp;&emsp;&ensp;
            <input type="radio" name="gender" id="male" />
            <label for="male">Male</label>
            <input type="radio" name="gender" id="female" />
            <label for="female">Female</label>
            <br/>
            <p>For what purpose(s) you are making account?</p>
            <input type="checkbox" id="app" name="purpose" value="storingapps" />
            <label for="app">Storing Apps</label>
            <input type="checkbox" id="site" name="purpose" value="storingsites" />
            <label for="site">Storing Sites</label>
            <input type="checkbox" id="fun" name="purpose" value="fun" />
            <label for="fun">Fun</label>
            <br/>
            <input type="submit" value="Submit"  class="button" />
        </form>
    </center>
</div>

Answer 1

When you push the submit button, you start the form submission process.

First the onsubmit function runs. This modifies your array.

Then the form submits and loads a new page.

This is (presumably) the same page that the user is already looking at. It's a fresh copy of it though, so it doesn't contain the array from the old version of it.

---

You can return false; at the end of the onsubmit function to prevent form submission.

Modern code would use addEventListener (introduced about two decades ago) and call the preventDefault method of the event object.

document.querySelector("form").addEventListener("submit", subm);
function subm(event) {
    event.preventDefault();
    // etc
}