WOLFRAM LANGUAGE TUTORIAL

Manipulating Elements of Lists

Many of the most powerful list manipulation operations in the Wolfram Language treat whole lists as single objects. Sometimes, however, you need to pick out or set individual elements in a list.

You can refer to an element of a Wolfram Language list by giving its "index". The elements are numbered in order, starting at 1.

{a,b,c}a list
Part[list,i] or list[[i]]the i^(th) element of list (the first element is list[[1]])
Part[list,{i,j,}] or list[[{i,j,}]]a list of the i^(th), j^(th), elements of list
Part[list,i;;j]a list of the i^(th) through j^(th) elements of list

Operations on list elements.

This extracts the second element of the list.
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This extracts a list of elements.
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This assigns the value of to be a list.
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You can extract elements of .
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By assigning a variable to be a list, you can use Wolfram Language lists much like "arrays" in other computer languages. Thus, for example, you can reset an element of a list by assigning a value to .

Part[v,i] or v[[i]]extract the i^(th) element of a list
Part[v,i]=value or v[[i]]=valuereset the i^(th) element of a list

Arraylike operations on lists.

Here is a list.
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This resets the third element of the list.
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Now the list assigned to has been modified.
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