equivalent of swift & in javascript-CodePudding

I'm not able to get the same djbhash in javascript that I was getting in swift.

extension String {
    public func djbHash() -> Int {
        return self.utf8
            .map {return $0}
            .reduce(5381) {
                let h = ($0 << 5) &  $0 &  Int($1)
                print("h", h)
                return h
            }
    }
}

var djbHash = function (string) {
    var h = 5381; // our hash
    var i = 0; // our iterator

    for (i = 0; i < string.length; i  ) {
        var ascii = string.charCodeAt(i); // grab ASCII integer
        h = (h << 5)   h   ascii; // bitwise operations
    }
    return h;
}

I tried using BigInt but the value for QHChLUHDMNh5UTBUcgtLmlPziN42 im getting is 17760568308754997342052348842020823769412069976n compared to 357350748206983768 in swift

CodePudding user response：

The Swift & operator is an “overflow operator”: It truncates the result of the addition to the available number of bits for the used integer type.

A Swift Int is a 64-bit (signed) integer on all 64-bit platforms, and adding two integers would crash with a runtime exception if the result does not fit into an Int:

let a: Int = 0x7ffffffffffffff0
let b: Int = 0x7ffffffffffffff0
print(a   b) //