我如何在Elixir函数中使用匹配的参数 [英] How do I used matched arguments in elixir functions

问题描述

说我有一个函数的两个用例。对有订阅的用户进行处理，对没有订阅的用户进行处理。

Say I have two use cases for a function. Do something with users that have a subscription and something with users that don't have a subscriptions.

def add_subscription(subscription_id, %User{subscription: nil})
  # Do something with user here.

和

def add_subscription(subscription_id, user)

我该如何进行模式匹配

谢谢！

推荐答案

您可以将函数参数绑定到变量：

You can bind the function argument to a variable:

def add_subscription(subscription_id, %User{subscription: nil} = user)

约定是在模式匹配后分配：

The convention is to assign after the pattern match:

# Do This
def foo(%User{subscription: nil} = user)

# Instead of this
def foo(user = %User{subscription: nil})

这篇关于我如何在Elixir函数中使用匹配的参数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！