MyString

MyString.java

package homeWork.myString;

/**
 * Created by mykhailov on 29.05.2016.
 */
public class MyString {
    private char[] chars;
    private int length;

    public MyString() {

    }

    public MyString(String str) {
        length = str.length(); //Yanchevskaya A. Нет проверки str на null
        chars = new char[length]; //Yanchevskaya A. Это лишнее действие, см. метод toCharArray()
        chars = str.toCharArray();
    }

    public MyString(char[] ch) {
        int count = ch.length; //Yanchevskaya A. Нет проверки ch на null
        chars = new char[count];//Yanchevskaya A. Можно написать chars = ch
        System.arraycopy(ch, 0, chars, 0, count);
    }


    public String toString() {
        return new String(chars);
    }

    public char charAt(int index) {
        if ((index < 0) || (index >= chars.length))
            throw new StringIndexOutOfBoundsException(index);
        return chars[index];
    }


    public int length() {
        return length;
    }

    public MyString concat(MyString str) { //Yanchevskaya A. Нет проверки str на null
        int length = this.chars.length + str.chars.length;
        char[] temp = new char[length];
        System.arraycopy(this.chars, 0, temp, 0, chars.length);
        System.arraycopy(str.chars, 0, temp, this.chars.length, str.chars.length);
        return new MyString(temp);
    }


    public int indexOf(int ch, int fromIndex) {
        if (fromIndex < 0) //Yanchevskaya A. Возвращаем -1
            fromIndex = 0;
        else if (fromIndex >= length)
            return -1;

        for (int i = fromIndex; i < length; i++)
            if (chars[i] == ch)
                return i;
        return -1;
    }


    public boolean equals(Object o) {
        MyString other;
        if (!(o instanceof MyString))
            return false;
        else
            other = (MyString) o;

        if (this.chars.length != other.chars.length)
            return false;

        int i = 0;
        while (i < this.chars.length) {
            if (this.chars[i] != other.chars[i])
                return false;
            i++;
        }
        return true;
    }


    public MyString toLowerCase() {
        char[] charCopy = new char[chars.length];
        for (int i = 0; i < chars.length; i++) {
            charCopy[i] = Character.toLowerCase(chars[i]);
        }
        return new MyString(charCopy);
    }


    public MyString toUpperCase() {
        char[] charCopy = new char[chars.length];
        for (int i = 0; i < chars.length; i++) {
            charCopy[i] = Character.toUpperCase(chars[i]);
        }
        return new MyString(charCopy);
    }


    public MyString substring(int beginIndex, int endIndex) {
        int sublength = (endIndex - beginIndex + 1); //Yanchevskaya A. Нет проверки входящих данных
        char[] subchars = new char[sublength];
        System.arraycopy(chars, beginIndex, subchars, 0, sublength);
        return new MyString(subchars);
    }


    public MyString trim() {
        int frontSpaces = 0, backSpaces = 0;
        int i = 0;
        //count spaces in front
        while ((i < length) && (chars[i++] == ' '))
            frontSpaces++;

        i = length - 1;
        //count spaces in back
        while ((i >= frontSpaces) && (chars[i--] == ' '))
            backSpaces++;

        MyString result = new MyString();
        if ((frontSpaces + backSpaces) <= length) {
            result.length = this.length - frontSpaces - backSpaces;
            result.chars = new char[result.length];
            System.arraycopy(chars, frontSpaces, result.chars, 0, result.length);
        }
        return result;
    }

    public MyString contains(MyString string) { //Yanchevskaya A. contains - это булевский метод, проверяет является ли переданная строка частью данной
        System.arraycopy(string.chars, 0, chars, 0, string.chars.length);
//        for (int i = 0; i < string.chars.length; i++)
//            chars[i] = string.chars[i];
        return string;
    }
}