Email verification (React Native). Return result as "invalid" for all records

Question

I am trying to check users email by checking it against expression. But the result that I get is not valid for all records.

UPDATED CODE

class dummytest extends Component{

  constructor(props){
    super(props);
    this.state = {
                email :'',
                validated: false ,
                 }
  };

go = () => {
           const reg = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
           if (reg.test(this.state.email) === true){
               alert( valid);
           }
           else{
               alert();
           }
 }
  render(){
       return(
         <View style={{alignSelf:'center',marginTop:100}}>
              <TextInput autoCapitalize="none" autoCorrect={false} style={{height:20,width:200,backgroundColor:'blue'}} value={this.setState.email}/>

              <Button onPress={this.go.bind(this)}>
                 <Text> GO </Text>
              </Button>
          </View>

       );
    }
}

Answer 1

Ok, I got a code that works below, you can take a look at the email check on each user input.

• Your functional part:

  validate = (text) => {
  console.log(text);
  let reg = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/ ;
  if(reg.test(text) === false)
  {
  console.log("Email is Not Correct");
  this.setState({email:text})
  return false;
    }
  else {
    this.setState({email:text})
    console.log("Email is Correct");
  }
  }
  

• You TextInput Component:

      <TextInput
        placeholder="Email ID"
        onChangeText={(text) => this.validate(text)}
        value={this.state.email}
      />
  

Answer 2

. validate go.

, , - , .

, :

• validate (email)
• this.state.email go
• , , .

- :

this.state = {
 email :'',
 validated : false,
}

...

go = () => {  
        if (this.state.email.test(/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/)==0) {
            this.setState({ validated : true });
        } else {
            this.setState({ validated : false });
        }
    }

Answer 3

validate = (text) => {
console.log(text);
let reg = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/ ;
if(reg.test(text) === false)
{
alert("Email is Not Correct");
this.setState({email:text})
return false;
  }
else {
  this.setState({email:text})
  alert("Email is Correct");
}
}


You can put this function validate in onChangeText propert of TextInput

Answer 4

Helper :

export default class Helper {

     static isEmailValid(email) {
        let reg = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
        return reg.test(email) == 0;
   }
}

if (Helper.isEmailValid(this.state.emailText)) {
    console.log("Email is correct");
} else {
    console.log("Email is not correct");
}