FrontEndDev

I have been working my way through the book and understood a lot of the concepts up until the Today.js file in Chapter 7. I really cannot get my head around what is going on with the code. I understand that the following occurs: When the window has loaded the event listener will call the init function. The init function will create a variable called today which will store the current date and time for the user. A variable called message will also be created which will generate a string to inform the user of the current time. I am not too sure what setText('output', message); does. It looks the 'output' and message values are being passed to the setText function. What is the 'output' value being passed to the function and what is setText's purpose? Once the setText function is called it has two parameters/arguments. These are elementId and message. The function's parameters are validated to ensure that both values are strings. The message value will presumably be the message "Right now it is Date, Hours, Minutes". But what is the elementId string? I thought that 'output' and message were being passed to the function so am not sure why it is validating elementId. A variable called output is created which should obtain an ID called elementId as an argument. I thought the getElementById method checks the HTML content for an id of elementId. The only reference to elementId I can find is within the JavaScript file. An IF statement is then used to check whether to use textContent or innerText for displaying the message. How does it return the message to the HTML as there does not appear to be any reference to the paragraph element's id of ouput in the HTML file? Sorry for all the questions, however, I am really struggling with this chapter Many thanks in advance.

Thank you for taking the time to reply and post the link to the website. I am afraid it has not really improved my understanding of the properties. I have read part of Chapter 9 which mentions that document.write is undesirable. I presume that innerText and textContent are therefore preferable? I have also stumbled across innerHTML as well which has only confused me further. Am I correct in saying that innerHTML can be used to display text in HTML format which means that it can be modified to be for example, bold, italic, red, etc? Whereas innerText would display the text in Plan Text which has no formatting whatsoever? I would like to understand this as I am sure it will come in useful in the future and would be good to know when to use it.

Hi all, I have recently purchase Larry Ullman's book, Modern Javascript, and working my way through each of the chapters. I have reached Chapter 6 - Complex Variable Types and have got stuck on page 179. As I work my way through the book I have been making lots of comments in my Javascript files to ensure that I fully understand the purpose of each line of code. However, when it has come to the code with textContent and innerText I have got stuck. For the example which displays today's date and time (page 178) I do not know why the textContent and innerText properties are used. From what I have gathered, textContent works in Firefox, while innerText works in Internet Explorer. What is the purpose of using them? Are they both used to ensure the date and time are displayed in both Firefox and IE? The code I am querying is: From what I have read the code will display the following message if the output ID in the HTML document is undefined, "Right now it is January 19, 2014 at 19:42". Would the document.write method work as well or is not appropriate for the task? Sorry if this is a really stupid question. I have tried searching for an answer on Google but am overwhelmed by the number of websites which only confused me further or use terminology I do not understand. I moved on to the section on arrays but it is used there as well so thought it would be a good idea to fully understand the purpose of the properties before moving on.