如何在React Native中访问状态中的外部函数值

Question

我正在尝试映射“ socialMediaDetail”数组并获取其名称。此数组中有任何值。现在，我试图从该数组中获取Twitter，然后在状态中获取该值。我该怎么办，请帮忙。

下面是数组vakue

socialMediaDetails:
socialMediaDetail: Array(5)
0:
link: "HARIRAM@twitter.com"
name: "twitter"
__typename: "SocialMediaDetail"
__proto__: Object
1:
link: "VarnaHERO@facebook.com"
name: "facebook"
__typename: "SocialMediaDetail"
__proto__: Object
2:
link: "linkedIn@linkedin.com"
name: "linkedIn"
__typename: "SocialMediaDetail" 

下面是代码

 class UpdateNotificationpreference extends Component {
      constructor(props) {
        super(props);
        const{navigation}=this.props;
        const{contactDetails,socialMediaDetails}= navigation.state.params.customerInfo[0];
        const{socialMediaDetail}=socialMediaDetails;
        socialMediaDetail.map((data, index) => {
          const twitter= data.name==="twitter";
        });
        this.state = {
          title: 'Update Notification Preference',
          mobile: navigation.state.params.serviceNumber,
          icon: 'sim',
          isChecked: false,
          facebook: navigation.state.params.customerInfo[0].socialMediaDetails.socialMediaDetail[1].name==="facebook"?true : false,
          isTwitter:this.twitter==="twitter"?true:false,

          render(){
          return(
          {this.state.isTwitter === true &&
                        <View style={{marginTop:15}}>
                          <Label img={FAX_MINI} textLabel="FAX"/>
                          <Item style={{borderColor: '#00fff', borderBottomWidth:1, marginLeft:0}}>
                            <Input
                              value={this.state.faxNum}
                              onChangeText={(text) => this.setState({faxNum:text})}
                            />
                          </Item>
                        </View>}
          )
          }

谢谢