js window.onload method of loading multiple functions_javascript skills

The usage is as follows:
function func(){alert("this is window onload event!");return;}
window.onload=func;
or as follows:
window.onload=function( ){alert("this is window onload event!");return;}

But window.onload cannot load multiple functions at the same time.

For example:

Copy code The code is as follows:

function t() {
alert("t")
}
function b(){
alert("b")
}
window.onload =t ;
window.onload =b ;

will overwrite the previous one, and the above code will only output b.
The following method can be used to solve this problem:

window.onload =function() { t(); b(); }

Another solution is as follows:

Copy code The code is as follows:

function addLoadEvent(func) {
var oldonload = window.onload;
if (typeof window.onload != 'function') {
window.onload = func;
} else {
window.onload = function() {
oldonload();
func();
}
}
}

is used as follows:

Copy code The code is as follows:

function t(){
alert("t")
}
function b(){
alert(" b")
}
function c(){
alert("c")
}
function addLoadEvent(func) {
var oldonload = window.onload;
if (typeof window.onload != 'function') {
window.onload = func;
} else {
window.onload = function() {
oldonload();
func ();
}
}
}

addLoadEvent(t);
addLoadEvent(b);
addLoadEvent(c);
//Equivalent to window.onload =function() { t(); b(); c() ;}

Personally, I think using implicit functions directly (such as: window.onload =function() { t( ); b(); c() ;}) is faster, and of course using addLoadEvent is more professional, so everyone should do what they want!