The infixed operators =>, :=, and =< can all store a value in a variable, but their arguments are in different order. (See Section 5.4.2 and Section 5.4.3.) Also, := and =< have different effects when the first argument is an element of a list stored in a variable, since =< modifies list elements by reference (see section 12.2.10).
However, suppose you have entered:
A:= [0,1,2,3,4] |
B:= A |
and you want to change A[3].
will change both A and B:
Input:
Output:
⎡ ⎣ | 0,1,2,33,4 | ⎤ ⎦ | , | ⎡ ⎣ | 0,1,2,33,4 | ⎤ ⎦ |
Here, A pointed to the list [0,1,2,3,4] and after setting B to A, B also pointed to [0,1,2,3,4]. Changing an element of A by reference changes the list that A points to, which B also points to.
Note that multiple assigments can be made using sequences or lists. Both
and:
assign a the value 1, b the value 2, and c the value 3. If multiple assignments are made this way and variables are on the right hand side, they will be replaced by their values before the assignment. If a contains 5 and you enter:
then b will get the previous value of a, 5, and not the new value of a, 2.