propOrUndef (method)

propOrUndef

• propOrUndef<K, R>(key): R

• Get a field from a wrapped object. Return undefined if the field is missing or empty, or opt instance is None.

  Type Parameters

  • K extends string | number | symbol

  • R extends undefined | {}

  Parameters

  • key: K

  Returns R

  Example

  interface A {x?: number;}
  
  const aFull: A = {x: 4};
  opt(aFull).propOrUndef('x'); // 4
  
  const aEmpty: A = {};
  opt(aEmpty).propOrUndef('x'); // undefined