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POJava: Integer obj can't cast to Comparable
 

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  1. POJava: Integer obj can't cast to Comparable
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    <p>I'm having problems trying to pass an Integer object from a driver class as an argument for function of a SortedArray Generic class I created. From my driver class, I convert the user's int input into an Integer object to be cast onto Comparable of my SortedArray class.</p> <p>I continue to receive the error: "Exception in thread "main" java.lang.ClassCastException: java.lang.Integer cannot be cast to Comparable". I took a look at some of my classmates' source codes only to find little difference in setting the arguments/parameters yet they have their code working just fine. I've been looking for hours trying to find what error I've made and I still can't find why my Integer object can't be cast to Comparable.</p> <p>Here's a bit from my SortedArray Class</p> <pre><code>public class SortedArray implements Comparable{ public int size; public int increment; public int top; Comparable[] a = new Comparable [size]; public SortedArray(int initialSize, int incrementAmount) { top = -1; size = initialSize; increment = incrementAmount; } public int appropriatePosition(Comparable value) { int hold = 0; if(top == -1) { return 0; } else { for(int i = 0; i &lt;= top; i++) { if(a[i].compareTo(value) &gt; 0) { hold = i; break; } } } return hold; } public void insert(Comparable value) //The function that my driver class needs to access { //Shifting numbers to the top if(full() == true) { Comparable[] tempArray = new Comparable[top + increment]; for(int i= 0; i&lt; size; i++) { tempArray[i]= a[i]; a = tempArray; } size = top + increment; } if(a[appropriatePosition(value) + 1] != null) { for(int i = top; i &lt; appropriatePosition(value); i--) { a[i + 1] = a[i]; } } a[appropriatePosition(value) + 1]= value; } </code></pre> <p>Here's the code for my driver class that passes Integer Object insertObj as an argument for SortedArray's insert function.</p> <pre><code>public class IntDriver { public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); //Creating variables int data; boolean check = false; int choice; int size = 5; int increment = 3; SortedArray b = new SortedArray(size, increment); //Creating Menu while(check == false) { System.out.println("Please choose through options 1-6."); System.out.println("1. Insert\n2. Delete\n3. Clear\n4. Smallest\n5. Largest\n6. Exit"); choice = keyboard.nextInt(); switch(choice) { case 1: System.out.println("Type the int data to store in array location."); data = keyboard.nextInt(); Integer insertObj = new Integer(data); b.insert(insertObj);// Here's where I lay "insertObj" as an argument for the SortedArray function. System.out.println("The value " + data + " is inserted"); break; </code></pre>
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    1. USPowerlord
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      1. VTUpMod
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    1. COYou might try adding your full exception stack trace here.
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      1. USMichael Brewer-Davis
    2. COIn the code you posted, there is nothing being casted. Could you perhaps post an SSCCE that shows the behavior you describe? http://sscce.org
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      1. POJava: Integer obj can't cast to Comparable
      1. USBart Kiers
 

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