restrict special characters in reactNative TextInput

Question

I'm trying to prevent my TextInput from getting values like $,%,^,&,(,) etc . Basically my TextInput should allow letters only. My approach is as follows. But still i'm able to input these other characters. How can i prevent special characters from the TextInput

restrict(event) {
        const regex = new RegExp("^[a-zA-Z]+$");
        const key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
        if (!regex.test(key)) {
            event.preventDefault();
            return false;
        }
    }

                         <TextInput
                                underlineColorAndroid='transparent'
                                allowFontScaling={false}
                                style={styles.questionText}
                                onKeyPress={e => this.restrict(e)}
                                value={firstNameState}
                            />

Answer 1

I'm trying to prevent my TextInput from getting values like $,%,^,&,(,) etc . Basically my TextInput should allow letters only. My approach is as follows. But still i'm able to input these other characters. How can i prevent special characters from the TextInput

restrict(event) {
        const regex = new RegExp("^[a-zA-Z]+$");
        const key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
        if (!regex.test(key)) {
            event.preventDefault();
            return false;
        }
    }

                         <TextInput
                                underlineColorAndroid='transparent'
                                allowFontScaling={false}
                                style={styles.questionText}
                                onKeyPress={e => this.restrict(e)}
                                value={firstNameState}
                            />

Answer 2

I'm trying to prevent my TextInput from getting values like $,%,^,&,(,) etc . Basically my TextInput should allow letters only. My approach is as follows. But still i'm able to input these other characters. How can i prevent special characters from the TextInput

restrict(event) {
        const regex = new RegExp("^[a-zA-Z]+$");
        const key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
        if (!regex.test(key)) {
            event.preventDefault();
            return false;
        }
    }

                         <TextInput
                                underlineColorAndroid='transparent'
                                allowFontScaling={false}
                                style={styles.questionText}
                                onKeyPress={e => this.restrict(e)}
                                value={firstNameState}
                            />

Answer 3

I have to block special characters by this line of code.

var format = /[!@#$%^&*()_+-=[]{};':"\\|,.<>/?]+/;

if(format.test(string)){ }