How to declare volatile variables in Swift

Question

I want to convert to Swift from Objective-C code like following;

int sum = 0;
x = 1;
for (int i = 0; i < 100; i++) {
    sum += x;
}

x is ac

Answer 1

Original Code:

int sum = 0;
x = 1;
for (int i = 0; i < 100; i++) {
    sum += x;
}

==================

Need to replace with :

var sum = 0
public let x = 1
for i in 0..<100 {
    sum += x;        
}

Please let me know if any confusion is there in this.