Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

The main method receives its arguments from the command line, which in most (all?) OSes is string oriented. In other words, the information that Java will receive to call main, will already be in string form (and only string), so using Object[] for main would require programmers to add explicit casts to String each time they would want to use an argument as a string. Using String[] is therefor more logical, and leads to simpler code.

And of course, as Turing85 said in the comments, the legalistic point of view is that this is "because the JLS says so":

The method main must be declared public, static, and void. It must specify a formal parameter (§8.4.1) whose declared type is array of String.

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Why is the Java main method static?

What's the reason of main method to be static? Why isn't just public void main(String[] args)? I think I understand what static means, but I see no reason to be it here. Thank you.

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Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

Definition of Java Literals

Literals are syntactically representation of fixed value from the source. In Java, Literals are of majorly four types: Character, Boolean, Numeric, and String. So basically, these literals are a bunch of characters which store a constant value for any variable. These literals are of immutable characteristics, cannot be changed. Every time we create a new variable or a constant, we define a data type and then assign particular values. Now, when the compiler reads the value of a constant variable, it reads and interprets those values as Literals.

For example, const int abc = 123; here, abc is our variable name, which is constant and assigned a value of 123. Now this value of a constant variable, 123, is our literal. In Java, we have 5 types of major literals. Integer, Boolean, Floating-point, Characters, and String are the data types, for with literals represent. When we are to pass a fixed value into our program, we implement literals.

Types of Java Literals with Examples

We will now learn every literal mentioned above with explanation, Program for demonstration and output.

1. Integer

Octal, Binary, Decimal, and Hexadecimal numbers are used in as literal values for integer literals. Base 2, 8, 10, 16 numbers are allowed.

  • Binary: 0 and 1,
  • Octal: Base 8
  • Decimal: Base 10 and
  • Hexadecimal: Base 16.

Let us now demonstrate these Integer Literals with code.

Code:

public class literal_b { public static void main(String args[]) throws Exception{ int m = 1010; int n = 0110; int o = 0x7e4; int p = 0b101; System.out.println(m); System.out.println(n); System.out.println(o); System.out.println(p); } }

Code Explanation: With our public class, we have our main class within, and four integer variables declared. Our first int variable is ‘m’ with the value of 1010, which is a decimal form of a literal value. Then we have our second variable, ‘b’ with a literal value of 0110, which is in octal value. Next is our ‘o’ variable with a hexa-decimal value, 0x7e4 and finally, our binary form of a literal value, 0b101, which is our ‘p’ variable. Upon execution, these values, for various integer variables, will be compiled and read as respective form, as mentioned.

Executing the above code will return integer values; refer to the below-attached screenshot for proper output.

Output:

Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

2. Character Literals

just enclose any single character with single quotes, and it is now a character literal. There are 4 ways to specify a literal with char.

  • Simple Char Literal: char ab = ‘q’; this specifies the simple literal for the character data type.
  • Integral Literal: another method to specify literal chars is by integral literal. Values between 0 to 65535, in the form of Decimal, Hexadecimal or Octal, can be specified as char literals.
  • Unicode: char literals can be represented in a Unicode form, i.e. ‘\uxxx’, here this four x are the hexadecimal values.
  • Escape Sequence: Each and every escape character can be passed as char literals.

Now that we have understood the above ways to present a literal in char let’s demonstrate and execute code.

Code:

public class literal_b{ public static void main(String args[]) throws Exception{ char ch1 = 'a'; char ch2 = 0123; char ch3 = '\u0021'; System.out.println(ch1); System.out.println(ch2); System.out.println(ch3); System.out.println("\'  is a escape character"); } }

Code Explanation: Just like every other code, we have our public class and the main class within. Then we have declared three char variables as ch1, ch2, ch3, and values, respectively. Later three print statements. Values assigned to these variables are not plain numbers but codes, which the compiler will understand, and output will differ from the value.

Lastly, we have our escape character, which is a single quote. Refer below-attached screenshot for full detailed output.

Output:

Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

3. Boolean Literals

The simplest Literals are the Boolean ones, True or False. Here, literals represent the logical values: only two, as we know, for any boolean data type. As we know, in java, it truly represents the value of 1 while the value of 0 is represented by false. Let’s demonstrate a working example of Literals for Boolean Values.

Code:

public class literal_b { public static void main(String args[]) throws Exception{ boolean samlpeb1 = true; boolean samlpeb2 = false; System.out.println(samlpeb1); System.out.println(samlpeb2); } }

Code Explanation: We have our class and the main class within, then two boolean variables declared with respective values. Then we have our print statements, which will print the boolean values as assigned. Upon execution, the above code will print true and false. Refer to the below attached screenshot for the expected output.

Output:

Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

4. String

Anything that goes between double quotes, “literals” is a string literal. Similar to char, except string literals can consist of multiple characters and are enclosed between double-quotes.

The below code implements the string literal in the simplest way.

Code:

public class Main{ public static void main(String args[]) throws Exception{ String literalstr = "This is String Literal."; System.out.println(literalstr); } }

Code Explanation: We have our simple class and the main class within, then we have our single most String Variable and the simple string value assigned to it. When printed, it will simply print the string as it is. Whatever is found between the double quotes will be recognized as string literal and will be reflected in the output, as it is.

Refer to the below attached screenshot for the output.

Output:

Public class testfirstapp public static void main(String args int wer 0x123 System out println wer)

One of the highly important aspects is to understand the difference between a variable, a constant and a literal: Variables are used to store values for future use. Int a = 2 is an example of a data type with a variable name, and the value here is 2. Similar to variables, constants are used to store value, but values of constant variables cannot be changed once assigned; const int a = 3 is an example of constant, and the value of a, which is 3, will never be changed by any method, in case if any attempt is made to change the value, the compiler won’t accept it. Now, Literals are the values assigned to such variables and constants. Like earlier, a = 2 and a = 3, the values 2 and 3 are the literals.

Conclusion

Literals are values assigned to various variables, which differ in various forms. Whatever the input form, the compiler will understand the code, and the output will be as expected. We understood literals for Boolean, Integer, Character forms and implemented the understanding along with code. These literals are best applicable when we’re to pass a fixed value in code.

This is a guide to Java Literals. Here we discuss the definition and types of java literals with examples that include integer, character literals, boolean literals, etc. You may also look at the following articles to learn more –

  1. Java WindowListener
  2. Java Duration
  3. C# Literals
  4. C Literals