Java使用Scanner类从文本文件中读取每行数字，找到最大值

Question

Hello I'm a java beginner and I'm working on an assignment. I need to read in numbers from text file, then print out message if they are invalid

1st number (Int) needs to be 0~99999

2nd number (Int) needs to be 0~5

3rd number (double) needs to be 0~100.00

the txt file looks like this, the numbers represent student ID, extra credit, grade
51673 0 98.85 
19438 5 95.00 
00483 3 73.16

and here is what I have so far... any hint is greatly appericiated

public static void validateDate(File inputFile) 
        x = new Scanner(new File("xxx.txt");
        while(x.hasNext())!= null) {    
        int a = x.next();
        int b = x.next();
        double c = x.next();
)


if (a < 0 || a > 99999){ 
System.out.print("Ignoring student with invalid ID number " + a);
}
if ( b < 0 || b > 5){ 
System.out.println("Ignoring student " + a + " with invalid extra credit" + b);
}
if ( c < 0 || c > 100){
System.out.println("Ignoring student " + a + " with invalid grade " + c);
}

I also need to write another method to find max value of all the 3rd numbers, any suggestions?

Answer 1

Read the documentation of Scanner . Check what functions return int and double and use them instead of next(); . Also for maximum value simply take another variable max=0.0; and check if every c is greater than that. If yes then assign max with the value of c .

Please Note: I could have spoiled by spoonfeeding you but I chose giving hints because you'll learn that way.