Possible Errors in the jsremoveChild blind eye _ javascript skills

The possible errors of jsremoveChild's blind eye are displayed after you read the code. Structure:

The Code is as follows:

• A


• B


• C

If you run code 1:

The Code is as follows:

Var ul = document. getElementById ('Demo ');
Var liList = ul. getElementsByTagName ('lil ');
For (var I = 0; I <= liList. length; I ++ ){
Ul. removeChild (liList [I]);
}

If you are cheated like me, you can see the correct code to understand the reason!

The Code is as follows:

Var ul = document. getElementById ('Demo ');
Var liList = ul. getElementsByTagName ('lil ');
Var lilength = liList. length;
For (var I = 0; I <lilength; I ++ ){
Ul. removeChild (liList [0]);
}