Tulishajifunza huko nyuma kuwa map data inakuwa na key na value. Pia tulijifunza jinsi ya lutengeneza map. Hapa kwanza tutaziona njia mbili za kutengeneza map ambazo hatukuzisoma huko mwanzoni.

 

At runtime

Hapa tutatengeneza data ya map wakati program inakuwa ina run

 

void main() {

 var websites = {};

 websites['jina'] = 'bongoclass';

 websites['umri'] = 5;

 websites['mmiliki'] = 'binafsi';

 websites['hali'] = 'ipo hai';

 

 print(websites);

}

Hii itatupa matokeo haya:-

{jina: bongoclass, umri: 5, mmiliki: binafsi, hali: ipo hai}

 

Kwa kutumia constructor 

Tutakuja kujifunza zaidi kuhusu constructor kwenye OOP. kw aufupi hii ni njia ambay hutumika kutengeneza object moja kwa moja. Hapa tutatumia new map()

 

void main() {

 var websites = new Map();

 websites['jina'] = 'bongoclass';

 websites['umri'] = 5;

 websites['mmiliki'] = 'binafsi';

 websites['hali'] = 'ipo hai';

 

 print(websites);

}

{jina: bongoclass, umri: 5, mmiliki: binafsi, hali: ipo hai}

 

Map properties:

  1. Key hutumika kupata key za map
  2. Values hutumika kupata value za map
  3. Lenght hutumika kupata idadi ya item
  4. isEmpty  kuangalia kama map ni tupu
  5. isNotEmpty kuangali kama map sio tupu

 

void main() {

 var websites = new Map();

 websites['jina'] = 'bongoclass';

 websites['umri'] = 5;

 websites['mmiliki'] = 'binafsi';

 websites['hali'] = 'ipo hai';

 

 print('key');

 print(websites.keys);

 

 print('values');

 print(websites.values);

 

 print('length');

 print(websites.length);

 

 print('is empty');

 print(websites.isEmpty);

 

 print('is not empty');

 print(websites.isNotEmpty);

 

}

 

Map method

  1. addAll() hutumika kuongeza item kwenye map

void main() {

 var website = {'jina': 'bongoclass', 'umri': 5, 'mmiliki': 'binafsi', 'hali': 'ipo hai'};

 website.addAll({'lugha':'kiswahili'});

 

 print(website);

}

{jina: bongoclass, umri: 5, mmiliki: binafsi, hali: ipo hai, lufha: kiswahili}

 

  1. remove hutumika kuondoa item kwenye map. Utatumia key ya hiyo item

void main() {

 var website = {'jina': 'bongoclass', 'umri': 5, 'mmiliki': 'binafsi', 'hali': 'ipo hai'};

 website.remove('jina');

 

 print(website);

}

Kwa kutumia key jina tumeweza kuondoa item bongoclass

{umri: 5, mmiliki: binafsi, hali: ipo hai}

 

  1. clear() hii hutumika kufuta item zote kwenye map.

void main() {

 var website = {'jina': 'bongoclass', 'umri': 5, 'mmiliki': 'binafsi', 'hali': 'ipo hai'};

 website.clear();

 

 print(website);

}

Hii itatupa empty map {}

 

  1. forEach unapotaka kuifanyia kazi kila item katika map utatuma forEach ni kama tulivyoona kwenye list.

void main() {

 var website = {'jina': 'bongoclass', 'umri': 5, 'mmiliki': 'binafsi', 'hali': 'ipo hai'};

 website;

 

 

website.forEach((key,values) => print('${key}: ${values}'));

}

 

void main() {

 var website = {'jina': 'bongoclass', 'umri': 5, 'mmiliki': 'binafsi', 'hali': 'ipo hai'};

 website;

 

int z = 1;

website.forEach((x,y) => print('${x}: ${y}'));

}

 

Mwisho:

Somo linalofuata tutakwenda kujifunza jinsi ya kutengeneza library yetu wenyewe na kuifanyia kazi.