Maelezo ya JavaScript Objects
JavaScript objects huhifadhi data katika jozi za funguo-na-thamani (key-value pairs). Kila jozi ni sifa (property).
Sifa huhifadhi aina tofauti za data:
- Strings
- Namba
- Arrays
- Object nyingine
- Functions
Wakati function inapokuwa ndani ya object, huitwa method. Method huainisha kile ambacho object hufanya.
Mfano: const human = { firstName: "Virat", lastName: "Kohli", age: 30, fullName: function() { return this.firstName + " " + this.lastName } }
Katika mfano huu, firstName ni funguo (key) na "Virat" ni thamani (value).
Njia za kutengeneza objects:
Object Literals Tumia mabano ya
{}kufafanua sifa moja kwa moja. let user = { name: "Sourav", age: 23 };Object Constructor Tumia sintaksi ya new Object(). let user = new Object(); user.name = "Sourav";
Jinsi ya kupata sifa (properties):
- Dot notation: user.name
- Bracket notation: user["name"]
Unaweza kubadilisha objects baada ya kuzitengeneza. Unaweza kuongeza sifa mpya au kuondoa zilizopo.
Ili kuondoa sifa, tumia opereta ya delete: delete user.age;
Ili kuangalia ikiwa sifa ipo, tumia opereta ya in au hasOwnProperty: "name" in user; user.hasOwnProperty("name");
Objects hukusaidia kukusanya data na tabia zinazohusiana mahali pamoja. Hii hufanya kodi yako kuwa na mpangilio na rahisi kudhibiti.
Chanzo: https://dev.to/kamalesh_ar_6252544786997/objects-in-javascript-2kc9