put variables from shell inside ack-grep using alias

Question

I want to use ack-grep alias in .zshrc. Here is how my alias lookes like now:

alias 'ack'='ack-grep -C -i -G --match'

but what I need is to put strings from this:

% ack string1 string2

inside

alias 'ack'='ack-grep -C -i -G string1 --match string2'

How to make this?

Update

Here is the code that worked:

ack() { 
    case $# in
    1) args="$1";;
    2) args="$1 -G $2";;
    *) args="$@";;
    esac
    eval "ack-grep -iC $args"
}

In my case I need to use eval for using more than one variable.

Update 2

Updated code without security issues:

ack () {
    if (( $# == 2 )); then
        ack-grep -iC "$1" -G "$2"
    elif (( $# == 1 )); then
        ack-grep -iC "$1"
    else
        echo 'Sorry, function works only for one and two params. In other case use ack-grep. Reread .zshrc'
    fi
}

Answer 1

eval is rarely necessary.

ack () { 
    if (( $# > 2 )); then
        ack-grep -iC "$@"
    else
        ack-grep -iC "$1" ${2:+-G "$2"}
    fi
}

Update: here is an exact version of your first solution, without eval.

ack() { 
    case $# in
    1) ack-grep -iC "$1";;
    2) ack-grep -iC "$1" -G "$2";;
    *) ack-grep -iC "$@";;
    esac
}