浏览以下内容前,请点击并阅读 声明

对于6种基本的数字类型,java提供了相对应的类。Number类和六种细分的子类。

aaarticlea/gif;base64,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" alt="" />

  注意:Number除了这些子类以外,还有四个子类,其中BigDecimal和BigInteger用于高精度的计算,而AtomicInteger和AtomicLong则用于多线程程序,再次不作介绍。

java的数字类提供了一些功能,如各个数字类会定义一些常量 如最大值,最小值等,此外,这些类还包含一些能够将基本数据类型到字符串的相互转化,以及各进位制的转换。

下表类除了一些Number子类所共有的方法:

方法 描述
byte byteValue()
short shortValue()
int intValue()
long longValue()
float floatValue()
double doubleValue()

将该数字对象转化为基本数字类型,并返回

int compareTo(Byte anotherByte)
int compareTo(Double anotherDouble)
int compareTo(Float anotherFloat)
int compareTo(Integer anotherInteger)
int compareTo(Long anotherLong)
int compareTo(Short anotherShort)

将该数字对象与参数对比

boolean equals(Object obj)

判断该数字对象是否与参数相等,如果参数的类型与值和该数字对象相等,则返回true,对于Double和Float类型还有额外的要求,详见API文档

每个数字类还含有一些用于和字符串与各个进位制之间的转换的方法,以下以Integer为例列举:

 方法 描述
static Integer decode(String s) 将一个字符串转化成位一个Integer对象,字符串的形式可以使十进制(默认),八进制(以0开头)和十六进制(以0x开头)。
static int parseInt(String s) 返回一个整数(十进制)。
static int parseInt(String s, int radix) 返回一个字符串转化的整数 (radix 代表进位制, 10, 2, 8, 或者 16分别代表十进制,二进制,8进制和16进制 ) 。
String toString() 返回一个代表该数字的字符串
static String toString(int i) 返回代表一个指定基础类型的整数的字符串
static Integer valueOf(int i) 返回一个指定基础类型的整数所对应的Integer类
static Integer valueOf(String s) 返回一个由字符串转化的Integer 类,该字符串必须以十进制表示
static Integer valueOf(String s, int radix) 返回一个有字符串转化的Integer类,第二个参数指定进位制。

数字输出格式

  利用PrintStream(System.out是一个PrintStream对象)的printf和format方法能够将字符串和数字组合输出。其print方法和println方法只能输出单一对象。

  printf和format方法是相同的,使用语法为:

format(format, Object... )

其中,第一个参数format指定输出的格式,其后可跟若干个输出的对象,使用示例:

int i = 461012;
System.out.format("The value of i is: %d%n", i);

输出格式字符串由文本和格式标识符构成,格式标识符以%开始,以转换字符结束,转换字符是一个表明数据类型的字符,格式标识符中间可以有其他的标记和标识符,详见java.util.Formatter

此外,java.text.DecimalFormat类也可用于控制数字中的开始和结尾的零,前后缀,分组和小数点。

对于数字,java提供了Math类进行一些高级的书序运算如求绝对值,三角函数,指数函数等。

此外Math类还提供了ramdom方法用来产生一个随机数字:

// 0.0 <= Math.random() < 1.0,因此如下句子将产生一个0-10的随机整数
int number = (int)(Math.random() * 10);

如果需要产生一系列的随机数,还可用java.util.Random

Autoboxing

Autoboxing是java教程中的一个术语,简单说就是自动转化,在写java代码时,我们可以直接将基础数据类型赋值给其对应的java对象的变量,其中有一个自动转化的过程,这是由编译器自动完成的。如int赋值给Integer变量。反过来叫unboxing,其实也是一种自动转化,只是转换方向相反,姑且叫自动逆转化吧。

自动转化和自动逆转化在以下情况会发生:

  赋值及其它运算

  方法的参数传递

如:

public static int sumEven(Integer li) {
int sum = 0;
//取余操作符%和+=不能对Integer对象使用,此处编译器会将Integer对象转化成int类型(unboxing)
if (i % 2 == 0)
sum += i;
return sum;
}

java-数字类的更多相关文章

  1. java代码split分割数字类

    总结:正则表达式-- package com.c2; //写一个spli的用法,数字类 ===分割字符串 public class yqw { public static void main(Stri ...

  2. Java:类与继承

    Java:类与继承 对于面向对象的程序设计语言来说,类毫无疑问是其最重要的基础.抽象.封装.继承.多态这四大特性都离不开类,只有存在类,才能体现面向对象编程的特点,今天我们就来了解一些类与继承的相关知 ...

  3. 深入理解java虚拟机【Java Class类文件结构】

    Java语言从诞生之时就宣称一次编写,到处运行的跨平台特性,其实现原理是源码文件并没有直接编译成机器指令,而是编译成Java虚拟机可以识别和运行的字节码文件(Class类文件,*.class),字节码 ...

  4. JAVA - 大数类详解

    写在前面 对于ACMer来说,java语言最大的优势就是BigInteger,Bigdecimal,String三个类. 这三个类分别是高精度整数,高精度浮点数和字符串,之所以说这个是它的优势是因为j ...

  5. (转)《深入理解java虚拟机》学习笔记5——Java Class类文件结构

    Java语言从诞生之时就宣称一次编写,到处运行的跨平台特性,其实现原理是源码文件并没有直接编译成机器指令,而是编译成Java虚拟机可以识别和运行的字节码文件(Class类文件,*.class),字节码 ...

  6. Java 11 - Java String类

    Java String类 字符串广泛应用在Java编程中,在Java中字符串属于对象,Java提供了String类来创建和操作字符串. 创建字符串 创建字符串最简单的方式如下: String gree ...

  7. Java 9 - Java Number类

    Java Number类 一般地,当需要使用数字的时候,我们通常使用内置数据类型,如:byte.int.long.double等. 实例 int i = 5000; float gpa = 13.65 ...

  8. 八、java常用类

    目录 一.字符串相关类 String类 StringBuffer类 二.基本数据类型包装类 三.Math类 四.File类 五.枚举类 一.字符串相关类 1.String类 java.lang.Str ...

  9. Java Number类和Math类

    Java Number类 一般的,当需要使用数字的时候,我们通常使用内置数据类型,如:byte.int.long.double等. 然而,在实际开发过程中,我们经常会遇到需要使用对象,而不是内置数据类 ...

  10. Java-Runoob:Java Scanner 类

    ylbtech-Java-Runoob:Java Scanner 类 1.返回顶部 1. Java Scanner 类 java.util.Scanner 是 Java5 的新特征,我们可以通过 Sc ...

随机推荐

  1. Stanford大学机器学习公开课(二):监督学习应用与梯度下降

    本课内容: 1.线性回归 2.梯度下降 3.正规方程组   监督学习:告诉算法每个样本的正确答案,学习后的算法对新的输入也能输入正确的答案   1.线性回归 问题引入:假设有一房屋销售的数据如下: 引 ...

  2. Linux SNMP oid

    http://www.debianadmin.com/linux-snmp-oids-for-cpumemory-and-disk-statistics.html

  3. 16.迭代器模式(Iterator Pattern)

    using System; namespace ConsoleApplication9 { class Program { /// <summary> /// 迭代器模式提供了一种方法顺序 ...

  4. 微信支付开发(1) JS API支付V3版(转)

    http://www.cnblogs.com/txw1958/p/wxpayv3-jsapi.html 本文介绍微信支付下的jsapi实现流程 前言 微信支付现在分为v2版和v3版,2014年9月10 ...

  5. C# 面试宝典

    1.简述 private. protected. public. internal 修饰符的访问权限. private  私有成员 只有类成员才能访问 protected  保护成员 只有该类及该类的 ...

  6. c#将http调用返回额json中的有关中文的unicode转换为中文(转)

    转转地址:http://www.cnblogs.com/promise-7/archive/2012/11/05/2755515.html 中文转Unicode:HttpUtility.UrlEnco ...

  7. mysql 如何设置自动增长序列 sequence(一)

    背景:由于项目需要,必须用mysql设置主键自增长,而且想用字符串的.经过上网查找并且实验,终于做出了一套方案.现在就共享给大家! 解决思路:由于mysql不带sequence,所以要手写的,创建一张 ...

  8. [javascript] 使用闭包编写模块

    这是一篇[javascript the good parts]的读书笔记. 我们知道可以利用javascript 的prototype 特性为原始类型编写拓展模块.利用如下方法: Object.pro ...

  9. 使用pl/sql監控PROCEDURE執行時間

    創建表 CREATE TABLE PROCESS_TIMING_LOG (   PROCESS_NAME       VARCHAR2(50 BYTE),   EXECUTION_DATE     D ...

  10. wp8 入门到精通 聊天控件

    <Grid > <Grid x:Name="bubble_right" VerticalAlignment="Center" RenderTr ...