Java Programming Practice 1 (Numbers and Strings)

Number class

Math class

Random Numbers

Characters

Strings

String Length

Concatenating Strings

Creating Format Strings

Converting Strings to Numbers (반대도)

Getting Characters and Substrings by Index - the substring methods , other methods for manipulating strings

Searching for Characters and Substrings in a String - the substring methods

Replacing Characters and Substrings in a String - the substring methods

Comparing Strings and Portions of Strings

 

Manipulating Characters in a String

Manipulating Characters in a String

 

Lab 7

package edu.handong.csee.java.lab07.numbers;

import java.util.Random;

public class RandomNumberGenerator {
    private int firstNumber=0;
    private int secondNumber=0;
    private int randomNumber=0;

    public static void main(String[] args) {
        RandomNumberGenerator rng = new RandomNumberGenerator(Integer.parseInt(args[0]), Integer.parseInt(args[1]));
        rng.generateRandomNumber();
        System.out.println(rng.getRandomNumber());
    }

    public RandomNumberGenerator(int f, int s){
        if(f<=s){
            firstNumber=f;
            secondNumber=s;
        }
        else{
            firstNumber=s;
            secondNumber=f;
        }
    }

    public void generateRandomNumber() {
        Random rand = new Random();
        randomNumber = rand.nextInt(secondNumber-firstNumber+1)+firstNumber;
    }

    public int getRandomNumber() {
        return randomNumber;
    }
}

 

 

풀이 1

package edu.handong.csee.java.lab07.string;

public class FamilyNamePrinter {
    private String[] stringNames; 
    private String[] familyNames;

    public static void main(String[] args) {
        FamilyNamePrinter fnp = new FamilyNamePrinter(args[0]);
        fnp.printFamilyNames();
    }

    public FamilyNamePrinter(String names) {
        stringNames=names.replaceAll(", ",",").split(",");
        int len = stringNames.length;
        familyNames = new String[len];

        for (int i=0 ; i<len ; i++){
            familyNames[i]=stringNames[i].substring(stringNames[i].indexOf(" ")+1);
        }
    }

    public void printFamilyNames() {
        for (String s : familyNames) {
            System.out.println(s);
        }
    }
}

풀이 2

package edu.handong.csee.java.lab07.string;

public class FamilyNamePrinter {
    private String[] stringNames; 

    public static void main(String[] args) {
        FamilyNamePrinter fnp = new FamilyNamePrinter(args[0]);
        fnp.printFamilyNames();
    }

    public FamilyNamePrinter(String names) {
        stringNames=names.replaceAll(", ",",").split(",");
    }

    public void printFamilyNames() {
        for (String s : stringNames) {
            int idx = s.indexOf(" ");
            System.out.println(s.substring(idx+1));
        }
    }
}