Getting Data From Input Using JavaScript

I am trying to get a value out of a with JavaScript I am using the following code: Choose a number between 1 and 5 &

Solution 1:

You have not defined your id. Also I guess your input type should be number.

<input type='number' name="input" id="num">
       ^^^^^^^^^^^^               ^^^^^^^^

And to alert its value you need to use

alert(input.value) //.value is used to get value of input

Solution 2:

There are more than one problems with your code

1) You have to close the bracket of your function it should be

 document.getElementById('btn').onclick = function(){
    input = document.getElementById('num');
        alert(input); //To check what value is outputted
}  

2)

input = document.getElementById('num');

The getElementById() method returns the element that has the ID attribute with the specified value.

so ID attribute is essential here and in your code there is no ID attribute defined so you have to defined it first

like

<input type='number' id="num" name="input">

3) document.getElementById('num'); does not return the value of input field it returns object so if you want value then use the following code

document.getElementById('num').value;

4) your input type="number"

for the desired output you can use following code

Choose a number between 1 and 5 <input type='number' name="input" id="myid">

<button id="btn">Click me!</button>

JS

    var myButton = document.getElementById("btn");
myButton.onclick = function()
{
         alert(document.getElementById("myid").value); //where does id come from?
}

The above method is pure JS if you need jquery method you can refer below

$( "#btn" ).click(function() {
  var input=$("#myid").val();
    alert(input)
});

Solution 3:

getElementById() works on elements with id attribute. So, as you have not put id attribute in your input type, it is not able to find the element with id=num.
Just add id="num" in your input element and then you are good to go.