Java lab 3
Java lab3
Download lab 3 fp:/ss:ss@10.132.14133/ classes/07/071 程序设计B/LAB/ab3ab3neW fp:/s:ss@10.132.14133/ classes/07/071 程序设计B/ MATERIALS h JDK API 1 5 Zh CN.CHM
Download lab3 ▪ ftp://ss:ss@10.132.141.33/classes/07/071 程序设计B/LAB/lab3/lab3_new ▪ ftp://ss:ss@10.132.141.33/classes/07/071 程序设计B/MATERIALS/ JDK_API_1_5_zh_CN.CHM
Preview of lab2 安装JDK ■设置环境变量 > Path= D: Javaj2sdk 1.4.2 bin 命令文件 javac,java的路径 ClassPath “你的cass件和导入的类包的路径
Preview of lab2 ▪ 安装JDK ▪ 设置环境变量 ➢Path= D:\Java\j2sdk1.4.2\bin; 命令文件 javac, java..的路径 ➢ClassPath= .; 你的 .class文件和导入的类包的路径
Preview of lab2 书写java文件的编辑器 NotePad 源文件保存格式为java而不是tt >EditPlus 导入命令 javac and java Javac S(FileName) Java s(ilenamenoEXt
Preview of lab2 ▪ 书写 .java 文件的编辑器 ➢NotePad 源文件保存格式为 .java 而不是 .txt ➢EditPlus 导入命令javac and java Javac $(FileName) Java $(FileNameNoExt)
Number systems 十进制 Decimal(0~9) 二进制 Binary(0,1 八进制 Octal(0~7) n十六进制 Hexadecimal(0~9A,B,C,DE,F)
Number systems ▪ 十进制 Decimal(0~9) ▪ 二进制 Binary(0,1) ▪ 八进制 Octal(0~7) ▪ 十六进制 Hexadecimals(0~9,A,B,C,D,E,F)
Transform between Number Systems Binary分 Decimal >d=bn*2An+bn-1*2(n +b1*2A1+b02^0 Binary Hex >110101011001D59 Binary e> Octal >1101101011001今6531
Transform between Number Systems ▪ Binary Decimal ➢d=bn*2^n+bn-1*2^(n-1)+…+b1*2^1+b0*2^0 ▪ Binary Hex ➢1101|0101|1001 D59 ▪ Binary Octal ➢110|101|011|001 6531
Primitive Data Types 7 Java Types Primitive Reference boolean cha Numeric Integral Floating short long double
Primitive Data Types
Declaring Variables int flener double height, width; “ int not"int"or“NT
Declaring Variables ▪ int fileNum; ▪ double height,width; ▪ “int” not “Int” or “INT
Assignment Statements int x x=100;√ X=3.1415926:X float f f=3.1415926:X
Assignment Statements ▪ int x; ▪ x = 100; √ ▪ x = 3.1415926; X ▪ float f; ▪ f = 3.1415926; X
Type Casting float f f=3.1415926;Ⅹ f=3.1415926f f=31415926F;√ f=(foa31415926;√
Type Casting ▪ float f; ▪ f = 3.1415926; X ▪ f = 3.1415926f; √ ▪ f = 3.1415926F; √ ▪ f = (float)3.1415926; √
