python中的函数返回值

Question

我编写了以下代码：

def addInterest(balance, rate):
    newBalance = balance * (1+rate)
    return newBalance


def test():
    amount=1000
    rate=0.05
    addInterest(amount, rate)
    print("" ,amount)

test()

我预计输出是1050，但仍在打印1000。有人能告诉我我做错了什么吗？你知道吗

Answer 1

函数addInterest（）返回值1050，但不应用amount变量的更改，因为您没有作为引用变量传递（我认为python不支持引用变量）。必须将返回值存储到新变量中：

def addInterest(balance, rate):
    newBalance = balance * (1 + rate)
    return newBalance

def test():
    amount = 1000
    rate = 0.05
    # STORE RETURNED VALUE
    result = addInterest(amount, rate)
    # PRINT RETURNED VALUE
    print(result)

test()

Answer 2

您没有从AddInterest赋值：

amount = addInterest(amount, rate)