Task 1
History
This blog post is for Douglas Crawfords's video lecture on JavaScript. I learned that JavaScript is a popular and powerful programming language. JavaScript is not related to Java and is in fact completely independent of it. JavaScript is object oriented language and is also case sensitive. There are several design errors in the language of which some have been corrected and others have not. There were very bad implementations of JavaScript in its early stages, however, these have been improved in recent years. It is very hard to learn the language from books. Dave Flannigans book "JavaScript: The Definitive Guide" is highly recommended by Mr. Crawford.
I also learned that early development of the language began in 1992 at Sun Microsystems through Jim Gosling. The language was originally called Java. Netscape thought that this version of the language was too heavy to do certain functions in a web browser. These functions include such things as creating API's on the browser and form validation. Because of this Netscape decided to make a lighter version of the language, or a scripting language whose syntax was based on Java. This language was known as LiveScript. This was the first scripting language to be put into both a web browser and web server. The LiveScript name was later changed to JavaScript. Microsoft did a similar implementation of JavaScript to JScript. The name was changed because of legal reasons. Netscape standardized JavaScript through ECMA in order to prevent Microsoft from having control of the language. They did not succeed due to Microsoft's influence in ECMA. Microsoft held significant control of the language from that point forward.
Key Ideas
The key set of ideas of JavaScript are described in the lecture as follows:
The first idea is load and go delivery which means that the program is delivered as text in the browser.
The second key idea is loose typing . The benefits of loose typing according to is better expressive power which makes it easier to write programs.
The third key idea is that JavaScript treats objects as general containers.
The fourth key idea protypal inheritance. This means that objects inherit characteristics directly from other objects instead of using classes.
The fifth key idea is Lambda. Lambda uses functions as first class objects.
The sixth key idea is linkage through global variables.
Task 2
History
This blog post is for Douglas Crawfords's video lecture on JavaScript. I learned that JavaScript is a popular and powerful programming language. JavaScript is not related to Java and is in fact completely independent of it. JavaScript is object oriented language and is also case sensitive. There are several design errors in the language of which some have been corrected and others have not. There were very bad implementations of JavaScript in its early stages, however, these have been improved in recent years. It is very hard to learn the language from books. Dave Flannigans book "JavaScript: The Definitive Guide" is highly recommended by Mr. Crawford.
I also learned that early development of the language began in 1992 at Sun Microsystems through Jim Gosling. The language was originally called Java. Netscape thought that this version of the language was too heavy to do certain functions in a web browser. These functions include such things as creating API's on the browser and form validation. Because of this Netscape decided to make a lighter version of the language, or a scripting language whose syntax was based on Java. This language was known as LiveScript. This was the first scripting language to be put into both a web browser and web server. The LiveScript name was later changed to JavaScript. Microsoft did a similar implementation of JavaScript to JScript. The name was changed because of legal reasons. Netscape standardized JavaScript through ECMA in order to prevent Microsoft from having control of the language. They did not succeed due to Microsoft's influence in ECMA. Microsoft held significant control of the language from that point forward.
Key Ideas
The key set of ideas of JavaScript are described in the lecture as follows:
The first idea is load and go delivery which means that the program is delivered as text in the browser.
The second key idea is loose typing . The benefits of loose typing according to is better expressive power which makes it easier to write programs.
The third key idea is that JavaScript treats objects as general containers.
The fourth key idea protypal inheritance. This means that objects inherit characteristics directly from other objects instead of using classes.
The fifth key idea is Lambda. Lambda uses functions as first class objects.
The sixth key idea is linkage through global variables.
Task 2
The JavaScript addition program is written below.
<html>
<head>
<title>Addition</title>
<script type="text/javascript">
var x = '2';
var y = '2';
var z = parseInt(x) + parseInt(y);
alert(z);
</script>
<html>
<head>
<title>Addition</title>
<script type="text/javascript">
var x = '2';
var y = '2';
var z = parseInt(x) + parseInt(y);
alert(z);
</script>
</head>
<body>
<h1> The sum of 2 + 2 has been displayed in the alert window.</h1>
</body>
</html>
A link to the actual web page is here: http://www.fuzionsphere.com/addition.html
