Can some one explain what it means that Strings are immutable?

Question

I understand that it means strings can not be changed but im not sure if im following:

dessert = "Ice Cream" 'Ice Cream' dessert = "Ice Cream and Pie" 'Ice Cream and Pie'

I know im just changing the variable but the concept that strings are immutable is not making sense.

Answer 1 · 2018-05-22T22:02:04Z

May 22, 2018 10:02pm

A good way to think of it conceptually is first think of something that is mutable(can be changed). So lets take a list for example. Say you have a list of students.

students = ['Bob', 'Gary', 'Steven']. If you take out one of those students from the list (because its mutable) you still would have a list of students. So the variable would make sense.

Now think of a string. will use the variable name fruit.

fruit = "apple"

This is immutable because if you take out the a (index[0] of the string) you now have 'pple' which changes the complete value of that variable. At least thats how I like to think about it. Hope it was a little helpful. I supplied a link to a free python book I use that I found helpful. The link is in regards to the strings chapter.

https://automatetheboringstuff.com/chapter6/

Answer 2 · 2018-05-22T22:02:44Z

May 22, 2018 10:02pm

In your example you assign the variable "dessert" to a string. Then you re-assign that same variable to another string.

The important fact is that you are not changing the string itself, just changing the variable to refer to a different one.

Perhaps this example will better illustrate immutability:

x = "test"
print(x[2])  # this will show the letter 's'
x[2] = "n"   # this will cause an error because you cannot change the string itself

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Jeff Kwon

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Can some one explain what it means that Strings are immutable?

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Brandon Oakes

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Steven Parker

Steven Parker