What does it mean to call api?

API (Application Programming Interface) is a program interface that allows interaction and communication between different applications. Calling an API means using the interface provided by the API to access specific functions and services. These services can be services provided by remote data or other applications, or they can be services provided by the operating system itself. For developers, calling APIs can help them implement the required functions faster and more efficiently.

Before using the API, we need to first understand the purpose of the API and the services provided. The calling format and usage of the API also need to follow the provisions of the API documentation. Usually, we need to authenticate through API key or token etc. before we can use the services provided by the API. Various exceptions may be encountered during API calls, and we need to handle them according to the error codes and instructions provided in the API documentation.

Calling API is necessary for many applications in our daily life. For example, in a mobile application, we may call the weather API to obtain the weather forecast information of the current city; in a social media application, we may call the API of WeChat or QQ to implement functions such as logging in and sending messages; in an e-commerce application, We can call Alipay or WeChat payment API to implement online payment function. In general, API calls can help us implement rich functions faster and more efficiently and improve the user experience of the application.