For Custom Text Component Tutorial

App.js

import * as React from 'react';
import { Text, View, StyleSheet } from 'react-native';

export default function App() {
  return (
    <View style={styles.container}>
      <Text style={styles.h1}>Heading 1</Text>
      <Text style={styles.h2}>Heading 2</Text>
      <Text style={styles.h3}>Heading 3</Text>
      <Text style={styles.h4}>Heading 4</Text>
      <Text style={styles.h5}>Heading 5</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
  },
  h1: {
    fontSize: 20
  },
   h2: {
    fontSize: 18
  },
   h3: {
    fontSize: 16
  },
   h4: {
    fontSize: 14
  },
   h5: {
    fontSize: 12
  },
});