Understand common Java data types: Master data type concepts

Java is an object-oriented programming language with rich data types. Today we will introduce these commonly used data types one by one and use specific code examples to help you learn more. Well understood and mastered.

1. Basic data types:

The basic data types of Java include integer, floating point, character and Boolean. The following is their detailed introduction:

• Integer type (byte, short, int, long): used to store integer values, representing integers in different ranges. For example, the byte type can store integers between -128 and 127.

byte myByte = 10;
short myShort = 100;
int myInt = 1000;
long myLong = 10000L;

• Floating point type (float, double): used to store values ​​with decimals. The float type represents a single-precision floating point number, and the double type represents a double-precision floating point number.

float myFloat = 3.14f;
double myDouble = 3.14159;

• Character type (char): used to store a single character. Characters must be enclosed in single quotes.

char myChar = 'A';

• Boolean: used to represent true or false values. The Boolean type has only two values: true and false.

boolean myBoolean = true;

2. Reference data types:

In addition to basic data types, Java also provides reference data types. Reference data types include strings, arrays, classes, etc.

• String: used to store a set of characters. Strings are treated as reference data types in Java, not as primitive data types.

String myString = "Hello World";

• Array: used to store a fixed-length collection of similar elements. An array can be an array of primitive data types or an array of reference data types.

int[] myIntArray = {1, 2, 3, 4, 5};
String[] myStringArray = {"apple", "banana", "orange"};

• Class: Class is the core concept of object-oriented programming and is used to create objects. Classes are composed of data members and method members. We can use predefined classes or define new classes ourselves.

public class Person {
    String name;

    public void sayHello() {
        System.out.println("Hello, my name is " + name);
    }
}

Person person1 = new Person();
person1.name = "John";
person1.sayHello();

In Java, there are other commonly used data types, such as enumeration (enum), BigDecimal, BigInteger, etc. These data types can be used according to actual needs.

It is very important for programmers to master Java's data types. Only by deeply understanding their characteristics and usage can we better write efficient and reliable programs.

To summarize, this article introduces the common data types in Java in detail, including basic data types and reference data types, and illustrates their usage through specific code examples. I hope this article can help everyone better understand and master Java's data type knowledge.

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