试图创建一个狗计算，我做错了什么？

Question

So I'm new to JS and trying to create a basic dog calculator to find out dogs age in human years. 1 year for dogs = 7 human years.

I know I'm close because whenever I run it in console, I get "Your dog is NaN years old in dog years.!".

Here's my code:

Dog Age:<input type="number" id="dogage">


<button onclick="calculateDogAge()"></button>

<h2 id= "humanyears"></h2>


function calculateDogAge(age) {
    //1 year for dogs is equivalent to  7 human years
    var dogYears= 7 * age;
    console.log("Your dog is " + dogYears + " years old in dog years!!");
}
document.getElementById("dogage").innerHTML= humanyears [age];

Answer 1

You dont say where you call your function, but ¡its right..

you can return the dogage directly in the function:

function calculateDogAge(age) {
    //1 year for dogs is equivalent to  7 human years
    var dogYears= 7 * age;
    return dogYears;
}

You wrote:

document.getElementById("dogage").innerHTML= humanyears [age];

which makes no sense, what is humanyears? is it an array?

To get the input number, you first get the input as an element, and get its value, like this:

var inputAge=document.getElementById("dogage").value;

and then you call the function:

var dogAge=calculateDogAge(inputAge);

and finally you write the dog age, maybe in your h2 like this:

document.getElementById("humanyears").innerHTML=dogAge;