Check if Object Instance of Class — TypeScript

// Time:  O(n)
// Space: O(1)

function checkIfInstanceOf(obj: any, classFunction: any): boolean {
    if (obj === undefined) {
        return false;
    }
    while (obj !== null) {
        if (obj.constructor === classFunction) {
            return true;
        }
        obj = Object.getPrototypeOf(obj);
    }
    return false;
};