JavaScriptGreaseSpot - Code snippets - make an array persistent in globalStorage これを見た。 storage('user', 'taro'); ok(storage('user')=='taro'); storage('user', null); ok(storage('user')===void(0)); storage('user', {a:5}); ok(storage('user').a == 5); storage('user', [1,2,3]); ok(storage('user').length == 3); ok(storage('user')[0] == 1); function ok(exp){ exp? console.info('OK') : console.error('FAIL