reference - Selecting specific cells from a column in excel based on another column -

here table trying reference from:

**a**         **b** ---------------------- true          id 100 false         0 false         0 false         0 false         0 true          id 811 false         0 false         0 false         0 true          id 742 

basically want able here list cells in row b row true. or row b not 0. result should this:

**a**           id 100 id 811 id 742 

i'm sure there must easy way can't seem work out?

many in advance.

in c1 enter:

=if( a1,1,"") 

in c2 enter:

=if(a2,1+max($c$1:c1),"") 

and copy down. column c "marks" desired values. in d1 enter:

=if(rows($1:1)>max(c:c),"",index(b:b,match(row(),c:c,0))) 

and copy down. example:

note:

this method avoids using array formula.

edit#1:

if don't mind array formulas, in c1 enter array formula:

=iferror(index($b$1:$b$15,small(if($a$1:$a$15,row($a$1:$a$15)-min(row($a$1:$a$15))+1,""),row(a1))),"") 

and copy down.

array formulas must entered ctrl + shift + enter rather enter key.