Erlang practice on DAY 1

1. Make a list of two 3-tuples.  Bind to L.

2. Retrieve the second tuple in L.

3. Remove the first tuple from L, bind resulting list to L2.

4. Make a tuple that contains the list [1, 2], the 
    tuple {a, b}, the atom true.  Bind to T1.
    
5. Make a list that has the two tuples T1 and {100, 101}


In-class answers appended here:

1. Make a list of two 3-tuples.  Bind to L.
98> L = [ {1, 2, 3}, {a, b, c} ].


2. Retrieve the second tuple in L.
100> [ _, X] = L.
[{1,2,3},{a,b,c}]

101> X.
{a,b,c}

102> tl(L).
[{a,b,c}]

103> hd ( tl (L) ).
{a,b,c}


3. Remove the first tuple from L, bind resulting list to L2.

105> L2 = [ X | [] ].
[{a,b,c}]

106> L2.
[{a,b,c}]

107> L3 = tl(L).   % using L3 instead of L2
[{a,b,c}]

108> L3.
[{a,b,c}]


4. Make a tuple that contains the list [1, 2], the 
    tuple {a, b}, the atom true.  Bind to T1.

111> T1 = { [1, 2 ], {a, b}, true }.
{[1,2],{a,b},true}

5. Make a list that has the two tuples T1 and {100, 101}

L5 = [ T1, {100, 101} ] .
[{[1,2],{a,b},true},{100,101}]