var array = new Array(); var x = document.getElementById("in").value;

    function func() {
        for (var i = 0, j = 0; i < x.length; i++) {
            if ((x[i] >= "0") && (x[i] <= "9")) {
                array[j] = array[j] + x[i]
            } else if (x[i] = "+") {
                j + 1;
            } else continue;
        }
        for (var i = 0; i < array.length; i++) {
            document.write(array[i]);
        }
    }
</script>

처리