what is the meaning of b=a when a is a list?see my example please.
a=［1,2,3］b=a after a.append or other operater. a,b is always the same.
a=[1,2,3]; b=a; a.push(4) alert(a) alert(b) js also Ans : This is Reference
Yes as he pointed/elaborate out You have to do like this a=[1,2,3] b=a[:] #slice with empty will return copy form a.append(4)
Look up the difference between reference types and value types. Reference types only store the reference of the object, such as a list, so the value of the variable is just a link to the actual object. Multiple variables just means multiple links to the same object. You need to do a deep copy to make a new list if you want to keep the original one separate.
thanks for your help.～(￣▽￣～)~The fact is that if i can use a［list］ to do what i want ,why i use b instead?i will look up the usage of reference type.some example is also very helpful.Love you guys