submit(f) {
    console.log(f.value); 
}
<form #f="ngForm" (ngSubmit)="submit(f)">
    <input ngModel name="tytul" type="text" id="tytul">
    <button>Dodaj</button>
</form>

handleSubmit = e => {
    e.preventDefault();
    console.log('tytul: ' + e.currentTarget.tytul.value);
};
render() {
    return (
        <div>
            <form onSubmit={this.handleSubmit}>
                <input type="text" id="tytul" />
                <button>Dodaj</button>
            </form>
        </div>
    );
}

interface IMyInterface {
    private: int a;
    IMyInterface() { a = 0; }
    void mth1();
}

interface IMyInterface {
    private: int a;
    void mth1();
    int mth2() { return a; }
}

interface IMyInterface {
    void mth1();
    int mth2() { return 0; }
}

interface IMyInterface {
    void mth1();
    int mth2();
}