JS callback function (callback)

Callback function is to pass a parameterized function , Is to pass this function as a parameter to another main function , When that main function is executed , Then execute the function passed in as a parameter . Take the parameterized function of this process It's called a callback function . In other words, it is passed as a parameter to another function （ The main function ） The function of is called Callback function .

        Simply speaking ： Callback function means that someone else called this function , That is, the function is passed into another function as a parameter .

        1. Self defined functions

        2. I didn't call

        3. The function finally executes

 for example ：

function test(value){   // This is the callback function 
    console.log(value)
}
function main(test,value){ //test Pass it in as a parameter 
    console.log(value)   
    test(value)     //  I am a callback function 
}
main(test,' I am a callback function ')

Link to the original text ：https://blog.csdn.net/xinxin7789/article/details/122119035\