Destruct assignment of arrays
1. Simple assignment
2. Multi-dimensional array deconstruction assignment
3. Default value, only if the corresponding position on the right is undefined (null is not undefined)
4. If the left and right are not equal, the corresponding sign will be entered, and if not, the value will be assigned by undefined
More left than right
More right than left
Object assignment
1. Normal assignment. The order of the right side of the object can be scrambled
2. Default value assignment, same as array
3. The variable name is inconsistent with the attribute name
In other words, the internal mechanism of deconstructive assignment of an object is to find the property of the same name and then assign it to the corresponding variable. It is the latter, not the former, that is really assigned
4. The use of parentheses
If the object has been defined before the deconstruction, the deconstruction needs parentheses
String deconstruction
