- API : Application programming interface. It is a list of all classes that are part of the Java development kit (JDK). These pre-written classes provide a tremendous amount of functionality to a programmer when writing code.
- Applets: Basically a portion of java code that can be embedded into an HTML file and runs in a web-browser.
- ASCII : American Standard Code for Information Interchange. A standard set of values for representing characters. For example, the basic ASCII codes that a programmer would greatly benefit from knowing are: A-Z: 65-90, a-z: 97-122, 0-9: 48-57
- Keywords: Reserved words that have special meaning to the Java compiler and cannot be used as variable names. Eg: main, return, String, int etc.
- Operators: There are 3 types of operators, namely,
1. Unary (works on 1 operand), examples being + + and – –
2. Binary (works on 2 operands) examples being +, – , * , / , >, <, == etc…
3. Ternary (works on 3 operands) examples being ? :
- Loops: They are used when you want to run a piece of code several times without, examples: for, while
- Nested Loop: A loop inside a loop is called a nested loop. example: a for loop inside a for loop.
- Package: A set of classes that can be imported into a program. They have sets of classes to serve a particular function.
- String: A data type used to store a store words, sentences etc. You can choose to store numbers in this data type as well but you won't be able to perform calculations with them unless they are converted to int data type. They are always input-ted using double quotes. Eg: "Hello World!", "5", "lol" etc.
- Int: int is a data type is used to store integer values only. Calculations can be performed using them. Eg: 5, 6, 80, 97 etc.
- Double: Double is a data type used to store decimal values. Calculations can be performed using them. Eg: 5.60, 8.0, 4.7546 etc.
- Scanner: Scanner class can be used to accept input from the user. Scanner class needs to imported before being used by using import java.util.Scanner; After that, within the main method, you must write Scanner in=new Scanner(System.in); ( where in can be anything except keywords) before being able to accept input using it. The way to accept different data types is outlined in "Accept input using Scanner" subheading of the Sample Code section.
- Escape Sequences: In Java, a set of characters coming after a backslash(\) have a special meaning to the Java compiler. They're called escape sequences. Eg: \n, \t,\' and so on.