59. Absolute Value

How do you plan to solve it?

Use ternary operator as mentioned don't use case statement otherwise all cases won't pass.

module abs8_func (
    input  signed [7:0] a,
    output       [7:0] abs
);
    // ---------- Write function here----------

    function [7:0] abs8;
        input signed [7:0] a;
        begin
            abs8 = (a < 0) ? -a : a;
        end
    endfunction


    // Function called here
    assign abs = abs8(a);

endmodule