[Java4android] Variables for Java

video from:http://www.marschen.com/

1. What is a variable

2. Declaration of variables

3. What types are variables divided into?

What is a variable?

1. The computer is an extremely accurate machine;

2. To store information in a computer, you must indicate the location of the information store and the storage space required;

3. In Java into language, use the LIFE statement to accomplish the above tasks;

Declaring methods for variables

int age;

Variable type variable name means statement end

This statement allows the computer to allocate enough space to store an integer whose name is called Age. int is a Java-defined data type that is dedicated to storing integers of a certain size;

What types of variables are used?

Basic data type:

Integer type: Int (byte, short, int, long)

Floating-point type (float,double)

Character type: (char)

Boolean type: (Boolean)

Reference data type:

Classes (Class)

Interface (interface)

Array

Naming conventions for variables

1. Variable naming syntax specification

1. Should be preceded by a letter underline or dollar sign;

2. The following letter underlines the dollar symbol or number;

3.java variable name has no length limit;

4.java variable name is case sensitive

2. Camel naming law:

1. Variable names should use meaningful English words;

2. Variable name if there is only one word, all the letters are lowercase;

3. If a variable name consists of multiple English words, the first letter is capitalized from the second word;