jquery implementation check box select all and All

For the check box's checked checked property, it is really powerless to spit out the slot.

As you can see, when the check box does not set the Checked property, it is not selected by default, and in three other cases, setting the Checked property without setting the property value is empty, or the Checked property value is set to True/false, which is selected by default.

Let's look at the introduction of the world view:

Combined with the first instance, we can not set the Checked property to the checkbox, and use JS to set the Checked property value of the check box, as follows:

It's not hard to see that 3 is selected by default

Based on this, the selection and all the choice is very good to do, here only to paste from a recent project intercepted part of the code, pro-Test effective:

jquery implementation check box select all and All