Specific functions of some multi parameter functions

I can often encounter some js Function has more than one parameter , Let's tidy up today , It will be updated continuously ！！！

1. addEventListener()

We know that when clicking or other events trigger , Corresponding dom The element has three stages ： Capture —— The goal is —— Bubbling , The third parameter that can be distinguished is the capture phase ( From the outside in ) Or bubble stage ( From the inside out ), Similarly, we change the position of the following two functions , You can let dom Elements bubble and then capture .

addEventListener('onclick',function(){
console.log(' This is the capture phase ')
},true);

addEventListener('onclick',function(){
console.log(' This is the bubbling stage ')
},true)

2. sort

sort The method is js Array sorting ( Change the of the original array 7 One of the big methods ) Methods , Not transmitted by default , The elements in the array will follow unicode Sort . If , If we want him to rank from small to large , You can pass a function , as follows ：

[1,4,2,6,4,8,6].sort((a,b)=>a-b)

In fact, this is the abbreviation of a method , If you want to know something, you can check it .

3. splice、slice

These two methods , In the array , The effect of cutting . however splice Change the original array ,slice Return a new array .

splice( Start index , How many bits are cut in total )
slice( Start index , End index ( This one is not included ))

Besides ,slice It can also be used for cutting strings .

4.setTimeout()、setInterval

setTimeout and setInterval The third parameter , Commonly used in , For internal functions ( The second parameter ) The ginseng

function sum(x, y) {
    console.log(x+y)   //3
}
setTimeout(sum, 1000, 1, 2, 3);

The following is actually wrong , No delay effect ：

function sum(x, y) {
    console.log(x + y); //3
}
setTimeout(sum(1, 2), 1000);