# The `.` operator (in lvalue, on values)

## Assigns correctly when used on an `Object`

### Juttle

    function in1() {
      var v = { a: 1, b: 2, c: 3 };
      v.a = 4;

      return v;
    }

    function in2() {
      var v = { a: 1, b: 2, c: 3 };
      v.b = 5;

      return v;
    }

    function in3() {
      var v = { a: 1, b: 2, c: 3 };
      v.c = 6;

      return v;
    }

    function out() {
      var v = { a: 1, b: 2, c: 3 };
      v.d = 4;

      return v;
    }

    emit -from :0: -limit 1
    | put in1 = in1()
    | put in2 = in2()
    | put in3 = in3()
    | put out = out()
    | view result

### Output

    { time: "1970-01-01T00:00:00.000Z", in1: { a: 4, b: 2, c: 3 }, in2: { a: 1, b: 5, c: 3 }, in3: { a: 1, b: 2, c: 6 }, out: { a: 1, b: 2, c: 3, d: 4 } }

## Produces an error when used on a value of invalid type

### Juttle

    function f() {
      var v = null;
      v.b = 5;
    }

    emit -from :0: -limit 1
    | put result = f()
    | view result

### Warnings

  * Invalid operand types for "[]": null and string (b).