isWithdrawable method

gistfile1.java

/**
 * Determines if the given amount is withdrawable which is defined as:
 *  amount must be more than or equal to zero.
 *  amount must be less than or equal to balance
 * @author James W. Dunne
 */
public boolean isWithdrawable(double amount) {
    if (amount < 0 || amount > balance) {
        return false
    }
    
    return true;
}