React.js: conditional rendering does not load child component

Question

I need to render the child component during conditional rendering. It is not displayed in the current version. If you insert into the html markup, then there are no errors, the component is rendered normally. What could be my mistake with conditional rendering?

Parent component:

  export default class App extends Component {
            data = {
                email: "a@b.net",
                password: "adc"
            }
        
            state = {
                email: "",
                password: ""    
            }
        
            emailChange=(e)=>{
                this.setState({email: e.target.value});
                }
            passwordChange=(e)=>{
                this.setState({password: e.target.value});
            }
        
            buttonSubmit=(e)=>{
            let p=this.state.email===this.data.email
            && this.state.password===this.data.password ? <div><Page1/></div> : alert('poi');
                e.preventDefault()
            }
        
            render() {
        
                return (
            <Container component="main" maxWidth="xs">
            <CssBaseline />
                <form  noValidate autoComplete="off"
                onSubmit={this.buttonSubmit}>
                    <div style={{marginTop:"150px"}}>
                        <Grid container spacing={2}>
                            <Grid item xs={12} >
                        <TextField
                                id="outlined-name"
                                label="e-mail"
                                variant="outlined"
                                value={this.state.email}
                                onChange={this.emailChange}/>
                            </Grid>
                                <Grid item xs={12} >
                                <TextField
                                    className="MuiInput-input"
                                    id="outlined-name"
                                    label="password"
                                    variant="outlined"
                                    value={this.state.password}
                                    onChange={this.passwordChange}/>
                                </Grid>
                            <Grid item xs={12}>
                            <Button
                                    style={{width:'210px'}}
                                    type="submit"
                                    fullWidth
                                    variant="contained"
                                    color="primary"
                                    >
                                    Enter
                                </Button>
                                </Grid>    
                                </Grid>
                            </div>
                        </form>
                </Container>
                );
            }
        }       
    

Child component that is not rendered during conditional rendering:

 const Page1 =()=>{
        return (
                <div style={{height: "100vh"}}>
                    <Header/>
                    <Grid container spacing={3}>
                        <Grid item xs={3}>
                            <Paper><ButtonPage/></Paper>
                        </Grid>
                        <Grid item xs={12}>
                            <Paper><ButtonWindow /></Paper>
                        </Grid>
                    </Grid>
                </div>
                );
    }

Answer 1

You're just assigning your child component conditionally to a local variable p , that you never render. I'd change your logic like this:

buttonSubmit=(e)=>{
    let p=(this.state.email===this.data.email && 
      this.state.password===this.data.password) ? 
      <div><Page1/></div>
      : 
      null;

    this.setState({p: p});

    e.preventDefault()
}

render() {
    ...
    {this.state.p}
}