function last(list)

{

    console.log(arguments);

    console.log(list);

    if(arguments.length==1)

    {

        var type = Object.prototype.toString.call(list);

        console.log(type);

         if(type=='[object Number]')

         {

             return list;

         }

         return list[list.length-1];

    }

    return arguments[arguments.length-1];

}

function removeExclamationMarks(s)

{

    return s.replace(/!/g,'');

}

function getChar(c)

{

    return String.fromCharCode(c);

}

function invert(array)

{

    for (var item in array)

    {

        if(array[item]!=0)

        {

            array[item] = array[item] * -1;

        }

    }

    return array;

}

function invert(array)

{

    var b = [];

    for (var item in array)

    {

        if(array[item]!=0)

        {

            b.push(-array[item]);

        }

        else

        {

            b.push(0);

        }

    }

    return b;

}

function invert(array) { return array.map(i => i==0 ? 0 : -i); }

var array1 = ['a', 'b', 'c'];

array1.forEach(function(element) {

  console.log(element);

});