React state is changing automatically, when input is entered

Question

The state variable of index.js is changing automatically even without setState().

I was trying to make a form with submit and reset button. I needed the initial value of the state to reset the form. The initial value is in variable data. But when I edit form both state and data variable is changing

class User extends Component {

        state = {
          formData: data
        }     

    updateForm = (newerState) =>{
        console.log(this.state);
        console.log(data);    

    }

    submitform =(event)=>{
        event.preventDefault();
        let dataToSubmit = {};

        for(let key in this.state.formData){
            dataToSubmit[key]=this.state.formData[key].value;
        }
    }

    resetForm =()=>{
        console.log(data);
        this.setState({formData: data});
    }

    render(){

        return(

            <div>
                <form onSubmit={this.submitform}>

                    <FormFields 
                    formData= {this.state.formData}
                    change={(newerState)=>this.updateForm(newerState)}
                    />
                <button type='submit'>Submit</button>
                <button type='button' onClick={this.resetForm}>Reset</button>
                </form>
            </div>
        )
    }
}

I excepted: console.log(this.state); //user.js:12 console.log(data); //user.js:13

will output initial values of data.json but the output is

{element: "input", value: "ans", label: true, labeltext: "Ques1", config: {…}}
1: {element: "input", value: "ans", label: true, labeltext: "Ques2", config: {…}}
2: {element: "input", value: "ans", label: true, labeltext: "Ques3", config: {…}}

if I click backspace in all input field. 1,2,3 is deleted from data.value