Can spomebosy tell me why the result is 58, can anybody give me the math equation?

Question

int [ ] myArr = {6, 42, 3, 7};
int sum=0;
for(int x=0; x<myArr.length; x++) {
sum += myArr[x];
}
System.out.println(sum);

// 58

Answer 1

0 + 6 + 42 + 3 + 7 = 58

Answer 2

Because the sum of all arrays elements is 58

Answer 3

// when x = 0, myArr[x] = 6
// when x = 1, myArr[x] = 42
// when x = 2, myArr[x] = 3
// when x = 3, myArr[x] = 7

sum = 0
sum = sum + 6 +42 + 3 + 7
sum = 0 + 58