Back-end code challenge solutions

Question1.java

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+import java.util.ArrayList;
+import java.util.List;
+
+public class Question1 {
+
+	/* 
+   	 * A function that takes an integer n and returns a list of all prime between 0 and n.
+     * The function takes one parameter n, which represents the end of the range.
+   	 */
+	public List<Integer> primeNumbers(int n) {
+  		List<Integer> primeNumbersList = new ArrayList<Integer>();
+
+  		for (int i = 0; i <= n; i++) {
+    		boolean isPrime = true;
+
+    		// If the number n is less than 2, then it is not a prime number. 
+    		if (i < 2) isPrime = false;
+
+    		for (int j = 2; j <= i / 2; j++) {
+        		if (i % j == 0 && i != j) isPrime = false;
+    		}
+
+    		if (isPrime) primeNumbersList.add(i);
+  		}
+
+  		return primeNumbersList;
+ 	}
+}
+

Question2.java

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+import java.util.ArrayList;
+import java.util.List;
+
+public class Question2 {
+
+	public List<Integer> factorial(int n) {
+        List<Integer> factorialList = new ArrayList<Integer>();
+
+        int fact = 1;
+        for (int i = 0; i <= n; i++) {
+            if (i == 0) {
+                fact = 1;
+                factorialList.add(fact);
+            } else {
+                fact = fact * i;
+                factorialList.add(fact);
+            }
+        }
+
+        return factorialList;
+    }
+}

Question3.java

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+public class Question3 {
+	/*
+     * Match a case of type Int, String and float
+     */
+	public boolean equals(Object o) {
+        if (o instanceof Integer) {
+            return true;
+        } else if (o instanceof String) {
+            return true;
+        } else if (o instanceof Float) {
+            return true;
+        }
+
+        return false;
+    }
+}

Question4.java

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+public class Question4 {
+	public String containsNumber(String s) {
+		String result = null;
+
+		if (s.matches(".*\\d+.*")) {
+    		result = s.replaceAll("\\D+", "");
+    	}
+
+    	return "Some(" + result + ")";
+	}
+}
+

Question5.java

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+public class Person {
+
+    private String name;
+    private int age;
+
+    public Person(String name, int age) {
+        this.name = name;
+        this.age = Math.abs(age);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+}