javaSE-day01--对话框、逻辑判断

    科技2024-05-09  82

    1.对话程序

    //终端输入,并打印

    package day01; import java.util.Scanner; public class HellowWord { public static void main(String[] args) { Scanner a = new Scanner(System.in); String name = a.nextLine(); System.out.println(name); } }

    总结:

    输入一行可以用nextLine()

    输入一个整数用nextInt()

    输入如浮点数用nextDouble()

    main方法是整个类执行时的入口

    2.相加

    import java.util.Scanner; public class Add { public static void main(String[] args) { Scanner a = new Scanner(System.in); String first = a.nextLine(); String last = a.nextLine(); int first1 = Integer.parseInt(first); int last1 = Integer.parseInt(last); int add = first1 + last1; System.out.println(add) } }

    总结:

    强制类型转换->String到int:Integer.parseInt();

    3.逻辑判断

    package day01; import java.util.Scanner; public class PanDuan { public static void main(String[] args) { Scanner a = new Scanner(System.in); String name = a.nextLine(); if(name.equals("Tom")) { System.out.println("欢迎您,Tom"); }else if(name.equals("Jim")){ System.out.println("你好,Jim"); }else { System.out.println(name+"你在本系统没有访问权限"); } } }

    总结:

    判断两个字符串是否相等:name.equals();

    Boolean类型 :true 和 false

    package day01; import java.util.Scanner; public class Boolean { public static void main(String[] args) { Scanner a = new Scanner(System.in); String name = a.nextLine(); boolean aa =name.equals("a"); System.out.println("输入的 值是a:"+aa); } }

    总结:

    Boolean a = 2>3 则a=false
    Processed: 0.013, SQL: 8