JAVASCRIPT QUESTIONS AND ANSWERS
1. How do you test that a variable contains a valid number?
isNaN(varHere); //Returns true or false.
2. How do you display a confirmation?
confirm("Message Text Here");
3. What values can confirm() return?
True or false
4. How do you assign the return value of confirm() to a variable?
var answerVar = confirm("Message Text Here");
5. How do you access a page element by id?
document.getElementById(id);
6. How do you assign actions to the window onLoad event?
window.onload = function() {//actions here}
7. What are the four attributes of the <script> tag?
Type, Src, Charset, and Defer
8. In the <script> tag, how is the Type attribute used?
<script type="text/javascript"> //Used to denote the type of script being
used. Always this for JavaScript
9. In the <script> tag, how is the Src attribute used?
<script src="fileName.js"> //Used to denote external file for script use
10. In the <script> tag, how is the Defer attribute used?
<script defer="defer"> //Used to ensure the code doesn't run until the rest of
the page has been loaded
11. What is the command to display a prompt?
prompt("Text Here");
12. How do you assign the value from a prompt to a string?
var stringVar = prompt("Text Here");
13. How do you assign the value from a prompt to a non-string variable?
Using a parse. Example : var intVar = parseInt(prompt("Text Here"));
14. How do you assign a default value to a prompt?
Using the second parameter. Example: prompt("Enter Age:", "18");
15. How do you display an alert?
alert("Alert Text Here");
