Bereaksi batas input elemen asli
<TextInput value={this.state.text} maxLength={4} />
Dayanaohhnana
<TextInput value={this.state.text} maxLength={4} />
<TextInput
style={{height: 40, borderColor: 'gray', borderWidth: 1}}
onChangeText={(text) => this.setState({text})}
value={this.state.text}
maxLength = {8}
/>