In this episode we will be looking into what’s Synchronous and Asynchronous Programming and how do we do it Salesforce platform.
In Synchronous programming statements will be executed one after the other. Say, we have 10 lines of code, then each and every line will be execute one after the other. So first line has to be executed it's only then the execution jumps to the second line. Likewise, second line has to be executed, only after that execution jumps on to the third line, so one and so forth. So, If our first statement is dealing with fetching list of Account records, until we get the data, execution will not jump on to the next line.
Asynchronous Programming is a methodology in which statements will not be executed one after the other. let’s say we have 10 lines of code and one of the statements in these 10 lines is a
setTimeout() statement and lets go with the assumption that we want it to get executed after 10 secs. Then the execution comes to this
setTimeOut() statement and the moment the execution hits this statement, we are telling the computer I want to run this function but I don’t want to do it at least for a 10000 milliseconds in the future. So once 10 seconds from now gets passed that’s when I want this statement to get executed.
Often we use this format of coding when we want to get data from other systems or when we make AJAX calls and etc. So we make the call and the thread doesn’t know when the response is going to comeback. This is Asynchronous Programming.
We also discussed about other things in this episode. Please check it out.