Extension.java

package com.booleanuk.extension;

import com.booleanuk.helpers.ExtensionBase;

public class Extension extends ExtensionBase {
    /*
        Implement the following methods:

        1. add, which accepts two floats and returns a float (both floats added together)

        2. add, which accepts two doubles and returns a double (both doubles added together)

        3. subtract, which accepts two floats and returns a float (first float minus second float)

        4. subtract, which accepts a String and a char and returns a string with all instances of the provided char removed

        5. multiply, which accepts two ints and returns an int (first int multiplied by second int)

        6. multiply, which accepts a string and an int, and returns a string containing the provided string
        as many times as the provided int separated by a comma. E.g.
        multiply("Hello", 3) -> "Hello,Hello,Hello"

        7. multiply, which accepts an array of Strings that each contain a number, and an int
        The method should return an array of ints that contain the value of multiplying each String number by the provided int
        E.g.
        multiply(["2", "7", "3"], 3) -> [6, 21, 9]
     */

    // 1.
    public float add(float a, float b) {
        return a + b;
    }

    // 2.
    public double add(double a, double b) {
        return a + b;
    }

    // 3.
    public float subtract(float a, float b) {
        return a - b;
    }

    public String subtract(String a, char b) {
        String str = "";
        int length = a.length();

        for (int i = 0; i < length; i++) {
            if (a.charAt(i) != b) {
                str += a.charAt(i);
            }
        }
        return str;
    }

    public int multiply(int a, int b) {
        return a * b;
    }

    public String multiply(String a, int b) {
        String string = "";
        for (int i = 0; i < b; i++) {
            string += a;
            if (i < b - 1) {
                string += ",";
            }
        }
        return string;
    }

    public int[] multiply(String[] a, int b) {
        int length = a.length;
        int[] newArr = new int[length];

        for (int i = 0; i < a.length; i++) {
            int num = Integer.parseInt(a[i]);
            newArr[i] = num*b;
        }
        return newArr;
    }
}