Now we will see atomic elements of java. Java programs are a collection of white space identifiers, comments, literals, operators, separators, and keywords. The operators are described in the next article
Java is a free-form language. This means that you do not need to follow any special indentation rules. For example, the Example program could have been written all on one line or in any other strange way you felt like typing it, as long as there was at least one whitespace character between each token that was not already delineated by an operator or separator. In java, whitespace is a space, tab, or new line.
Identifiers are used for class names, method names, and variable names. An identifier may be any descriptive sequence of uppercase and lowercase letters, numbers or the underscore and dollar sign characters. They must not begin with a number, lest they be confused with a numeric literal. Again, java is case-sensitive, so VALUE is a different identifier the Value. Some examples of valid identifiers are:
AvgTemp count a4 $test this_is_ok
Invalid variable names include:
2count high-temp Not/ok
Using a literal representation of it creates a constant value in java. For example, here are some literals:
100 98.6 â€˜Xâ€™ â€œThis is a testâ€
Left to right, the first literal specifies an integer, the next is a floating-point value, the third is a character constant, and the last is a string. A literal can be used anywhere a value of its type is allowed.
As mentioned, there are three types of comments defined by java. You have already seen two: single-line and multilane. The third type is called a documentation comment. This type of comment is used to produce an HTML file that documents your program. The documentation comment begins with a /** and ends with a*/. Documentation comments are explained in Appendix A.
Most Viewed Articles (in Java )
Latest Articles (in Java)
Comment on this tutorial
- Data Science
- Cloud Computing
- Java Beans
- Mac OS X
- Office 365
- Tech Reviews