def change(amount: Int, coins: Array[Int]): Int = {
        val dp = Array[Int](amount + 1)
        dp(0) = 1
        for {
            coin <- coins
            i <- coin to amount
        } dp(i) += dp(i - coin)
        dp(n)
}

when I’m executing above method, I’m getting following error.

java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
    at Main$.$anonfun$change$2(HelloWorld.scala:9)

But, when I Initialize the Array with new keyword(as following) and execute it, It is executing perfectly and I’m getting correct output.

Why?

def change(amount: Int, coins: Array[Int]): Int = {
        val dp = new Array[Int](amount + 1)
        dp(0) = 1
        for {
            coin <- coins
            i <- coin to amount
        } dp(i) += dp(i - coin)
        dp(n)
}

I don’t know whether my understanding is correct or not, but only difference I found is mentioning new keyword. so my ask is, is there any connection to Array Initialization to get the ArrayIndexOutOfBoundExeption in the above methods, if yes, what is it?

I need Explanation in terms of Scala Programming.