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What is the use of the JavaScript immediate execution function? for this question, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible way.

We know that in general, a function must be called before it can be executed. As shown below, we define a function and call the

Function fn () {console.log (1);} fn ()

The print result is as follows:

If it is not called, the result we print will never be displayed.

So here we will mention our immediate execution function, which is a function that can be executed immediately without needing to be called.

There are two most common ways to write an immediate execution function:

(function () {}) ()

(function () {} ())

For example:

(function fn () {console.log (2);}) ()

The print result is as follows:

Print successfully.

Immediately executing the second parenthesis in the function is equivalent to calling the function. We can also pass parameters to the immediately executed function, and write the parameter we want to pass in the second () as an argument.

As follows:

(function fn (a _ r _ b) {console.log ('a+b='+a+b);}) (1 ~ 2)

The print result is as follows:

The second method of using the immediate execution function is basically similar to the first, and will not be repeated.

It is important to note that if there are multiple functions that execute immediately, they need to be separated by commas, otherwise an error will be reported. At the same time, in the immediate execution function, it can also be written in the form of anonymous function.

So what are the benefits or benefits of executing the function immediately?

Its greatest function is to create a scope independently. As we know, there is no concept of private scope in javascript. If some variables are declared in the global or local scope on a multi-person development project, others may accidentally overwrite them with variables of the same name, while the variables in the immediate execution function are all local variables, and there will be no naming conflicts.

This is the answer to the question about what is the use of the JavaScript immediate execution function. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel for more related knowledge.

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