If you don’t immediately plunge into the laconic syntax and functionality of JavaScript semantics, simple code examples will help you quickly learn how to increase the dynamics and efficiency of pages.
JS is a programming language "inside" the browser. JavaScript has solid experience working with page elements, original solutions in the field of object-oriented programming, "knows how" to communicate with the server, because numerous JavaScript code examples do not immediately become available for understanding and application.
General through quotient: simple beginning
Programming inside the browser is still relatively young, but quickly gained a high-quality and original experience. JavaScript received syntax and semantics from the titled "ancestors", and in terms of syntax functionality and practicality - from the time of pre-Internet programming languages, primarily C / C ++, Pascal.
Looking through JavaScript examples, one should not immediately try to understand the logic of thinking of authors and the functionality of algorithms - this is an unpromising task, it is better to focus on your own private practice.
Simply start by connecting the onload handler in the body tag and write the traditional "Hello" in the modern "I`m ready" style.
These JavaScript examples show:
- the onload event that occurs after the page loads is assigned a handler - the GoPage () function;
- the page loads and the GoPage () function takes control;
- calling the internal function of the alert language, which displays a message in the browser "I'm ready";
- The browser is waiting for a reaction from the visitor.
The comments provide descriptions of the actions that you usually need to do after loading the page and starting the timer.
Very handy: JS is very closely related to page elements. So, calling document.getElementById gives a link to a div with the identifier "scTimer". Using the dTimer.innerHTML = "any valid HTML code" construct , you can dynamically change the content of this div.
You should especially pay attention to the undesirability of errors in the body of JavaScript scripts. Examples of this cause negative consequences. The above code says alert ('I'm ready'), and it won’t work in any way. Any type of apostrophes is allowed to denote strings: both single and double, moreover, inside a pair of one kind, one can be used, the other as a symbol.
In this case, it should have been indicated: either alert ("I'm ready"), alert ('I`m ready'), alert ('I \' m ready '), or other combinations.
About JS Errors
At first there was a browser, on the initiative of the visitor, he loaded the page of the site, built the DOM tree and enabled JavaScript to act: provided him the opportunity to analyze the loaded page, initialize its elements, connect event handlers and establish contact with the server.
When analyzing JavaScript (examples), you need to pay attention to code debugging. This procedure rests more with the developer. The browser in which the work is performed may offer certain debugging tools, but practice shows that strict adherence to the language syntax, simplicity and correctness of the algorithm have a much greater effect to achieve a working result.