[{"id":296,"nama":"Appetizer"},{"id":295,"nama":"Bahan"}]

var obj = JSON.parse(response);

let str = '[{"id":296,"nama":"Appetizer"},{"id":295,"nama":"Bahan"}]';

try {
  let obj = JSON.parse(str);
} catch (ex) {
  console.error(ex);
}

JSON.stringify(obj)

try {
  let response = await fetch('http://'+this.state.url+'/web_services/login_json/new.json', {
                            method: 'POST',
                            headers: {
                              'Accept': 'application/json',
                              'Content-Type': 'application/json',
                            },
                            body: JSON.stringify({
                              erzap: {
                                username: this.state.username,
                                password: this.state.password,
                                  }
                            })
                          });
  let responseJson = await response.json();

AsyncStorage.getItem('kategoris').then((value) => {
    this.setState({
      'kategoris': value,
    });

  })