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I have a program that will ask the user to input their grades for 4 different sections of a project, then tell them what their total mark is, what grade they got and how many marks away they were from the next grade. I managed to make a single loop for all inputs rather than having a loop for each individual one, but there are still quite a lot of if statements to determine what grade they got and how far away they were from the next one, and I can't figure out how to optimise it since I'm still very new to Java.

import java.util.Arrays;

import java.util.InputMismatchException;

import java.util.Scanner;



public class PortfolioGrade {



    public static void main(String args) {

        // TODO Auto-generated method stub

        String words = new String{"Analysis", "Design", "Implementation", "Evaluation"};

        int marks = new int[words.length];

        for(int counter = 1; counter <= words.length; counter++) {

            System.out.println("Enter your mark for the '" + words[counter - 1] + "' part of the project: ");

            while(true) {

                try {

                    Scanner reader = new Scanner(System.in);

                    marks[counter - 1] = reader.nextInt();

                    if(marks[counter - 1] < 0 || marks[counter - 1] > 25) {

                        System.out.println("Please input a number between 0 and 25.");

                        continue;

                    }

                    break;

                } catch(InputMismatchException e) {

                    System.out.println("Please input a valid integer.");

                }

            }

        }



        int totalmark = Arrays.stream(marks).sum();

        String grade = null;

        String nextgrade = null;

        Integer marksaway = null;



        if(totalmark < 2) {

            grade = "U";

            marksaway = 2 - totalmark;

            nextgrade = "1";

        } else if(totalmark >= 2 && totalmark < 4) {

            grade = "1";

            marksaway = 4 - totalmark;

            nextgrade = "2";

        } else if(totalmark >= 4 && totalmark < 13) {

            grade = "2";

            marksaway = 13 - totalmark;

            nextgrade = "3";

        } else if(totalmark >= 13 && totalmark < 22) {

            grade = "3";

            marksaway = 22 - totalmark;

            nextgrade = "4";

        } else if(totalmark >= 22 && totalmark < 31) {

            grade = "4";

            marksaway = 31 - totalmark;

            nextgrade = "5";

        } else if(totalmark >= 31 && totalmark < 41) {

            grade = "5";

            marksaway = 41 - totalmark;

            nextgrade = "6";

        } else if(totalmark >= 41 && totalmark < 54) {

            grade = "6";

            marksaway = 54 - totalmark;

            nextgrade = "7";

        } else if(totalmark >= 54 && totalmark < 67) {

            grade = "7";

            marksaway = 67 - totalmark;

            nextgrade = "8";

        } else if(totalmark >= 67 && totalmark < 80) {

            grade = "8";

            marksaway = 80 - totalmark;

            nextgrade = "9";

        } else if(totalmark >= 80) {

            grade = "9";

        }



        System.out.println("Your total mark was " + totalmark + ".");

        System.out.println("You got a Grade " + grade + ".");

        if(grade == "9") {

            System.out.println("You achieved the highest grade!");

        } else if(marksaway == 1) {

            System.out.println("You were " + marksaway + " mark away from a Grade " + nextgrade + ".");

        } else {    

            System.out.println("You were " + marksaway + " marks away from a Grade " + nextgrade + ".");

        }

    }

}

Because there are no holes you can simply have an array of "breakpoints".

int  steps = new int { 2, 4, 13, 22, 31, 41, 54, 67, 80 };

int i;



for(i=0; i<steps.length && totalmark>=steps[i]; i++);

grade = i==0 ? "U" : ""+i;

if(i<steps.length) marksaway=steps[i]-totalmark; 

nextgrade=""+(i+1);

I tidied up the first section for you a bit and then implemented the technique suggested by @Holger, all seems to work perfectly after running a few tests.

import java.util.Arrays;

import java.util.InputMismatchException;

import java.util.Scanner;



public class MarkCalculator {



public static void main(String args) {

    // TODO Auto-generated method stub

    String words = new String{"Analysis", "Design", "Implementation", "Evaluation"};

    int steps = { 2, 4, 13, 22, 31, 41, 54, 67, 80 };

    int marks = new int[4];



    Scanner reader = new Scanner(System.in); // Keep instantiation of scanner outside of loop - once is enough



    int totalmark = 0; 

    int inputMark = 0;

    int marksaway = Integer.MIN_VALUE;



    String grade = "";

    String nextgrade = "";



    for(int counter = 0; counter<words.length; counter++) {

        System.out.println("Enter your mark for the '" + words[counter] + "' part of the project: ");

        try {

            do {

                inputMark = reader.nextInt();

                if(inputMark < 0 || inputMark > 25)

                    System.out.println("Please input a number between 0 and 25.");

                else

                    marks[counter] = inputMark;

            } while(inputMark < 0 || inputMark > 25);

        } catch(InputMismatchException e) {

            System.out.println("Please input a valid integer.");

            reader.nextLine();

            counter--;

        }

    }



    totalmark = Arrays.stream(marks).sum();



    for(int i=0; i<steps.length && totalmark>=steps[i]; i++) {

        grade = (i==0 ? "U" : ""+i);

        if(i < steps.length) {

            marksaway = steps[(i+1)]-totalmark; 

            nextgrade = "" + (i+1);

        }

    }



    System.out.println("Your total mark was " + totalmark + ".");

    System.out.println("You got a Grade " + grade + ".");

    if(grade == "9") {

        System.out.println("You achieved the highest grade!");

    } else if(marksaway == 1) {

        System.out.println("You were " + marksaway + " mark away from a Grade " + nextgrade + ".");

    } else {    

        System.out.println("You were " + marksaway + " marks away from a Grade " + nextgrade + ".");

    }

}

}