java编译变量的正确写法和控制台输入

一些变量的正确写法：

short s = 123;  

int i = 50000;  隐式转换

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byte b = (byte)200;

long l = 88888888888l;

float f = 12.345f;显式转换

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int b;

b = (int)(b + 0.3);

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控制台输入：
import java.util.Scanner;
public class TestScanner{
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        int a = Integer.parseInt(str);
        if(a>=90){
            System.out.println("优秀");
        }else if(a>=60&a<90){
            System.out.println("及格");
        }else{
            System.out.println("不及格");
        }
        scanner.close();
    }
}

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