two equal arrays, how do I add / remove elements to one array without changing the other?
two equal arrays, how do I add / remove elements to one array without changing the other?
b=a.slice ()
lodash clonedeep, learn about
Deep copy, shallow copy
if it is just an array and the original two refer to each other, you need to re-assign an equivalent new array to the variable to be operated on (deep copy one, but the two arrays are no longer equal, but the elements are the same)
for example, if an is the original array and b is the array to be operated, you can execute
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