About the resolution of the all-choice question just now.

Just put Input[i].setattribute (' checked ', true); change to Input[i].checked=true;

Input[i].removeattribute (' checked '); change to Input[i].checked=false; just fine.

Because setattribute sets the attribute property of input, and if an input is selected before clicking Select All, but the input node does not increase the checked property, there is no additional checked

Attribute property, when this input is selected, the increment should be the property of the JS object input, so you can also use the method in jquery. Prop () to modify the value of checked, where the input[i].checked= true; The property attribute of the JS object input is also modified.

About the resolution of the all-choice question just now.