Second Short Program Java
Perhaps no other concept is more fundamental to a programming language than that of a variable. As you may know, a variable is a named memory location that may be assigned a value by your program.
class Example2 {
public static void main(String args []) {
int num; // this declares a variable called num
num = 100; // this assigns num the value 100
System.out.println("This is num: " + num);
num = num * 2;
System.out.print("The value of num * 2 is ");
System.out.println(num);
}
}
Output
This is num: 100
The value of num * 2 is 200
This line declares an integer variable called num. Java (like most other languages) requires that variables be declared before they are used. Following is the general form of a variable declaration: type var-name; Here, type specifies the type of variable being declared, and var-name is the name of the variable. If you want to declare more than one variable of the specified type, you may use a comma-separated list of variable names. Java defines several data types, including integer, character, and floating-point. The keyword int specifies an integer type.
In the program, the line
num = 100; // this assigns num the value 100
assigns to num the value 100. In Java, the assignment operator is a single equal sign. The next line of code outputs the value of num preceded by the string “This is num:”.
System.out.println(“This is num: ” + num);
In this statement, the plus sign causes the value of num to be appended to the string that precedes it, and then the resulting string is output.
