技術探し

Optional Chaining github.com // before const fooInput = myForm.querySelector('input[name=foo]'); const fooValue = fooInput ? fooInput.value : undefined; // after const fooValue = myForm.querySelector('input[name=foo]')?.value; const obj = { foo: { bar: { baz: 42 } } }; obj?.foo?.bar?.baz; // 42 obj…