angularjs - Angular 2: Create drop-down list with array of dictionaries -

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• angular2 - error if don't check if {{object.field}} exists 1 answer

i'm using options tag in angular 2 populate dropdown list. dropdown list populating correctly datetest1.json, however, when iterating thru values of given key in .json file, it's having trouble populating drop down list. what's correct way in angular 2 populating dropdown list datetest.json example below?

*.component.html when retrieving datetest.json: exception: typeerror: cannot read property 'month' of undefined in [dateattributeslist.month in *component@63:22]

<option *ngfor="#m of dateattributeslist.month" [value]="m">{{m}}</option> 

datetest.json:

[     {"month": ["dec", "jan", ...]},     {"day" : ["1","2"...]} ] 

*.component.html when retrieving datetest1.json: correctly populating

<option *ngfor="#m of dateattributeslist" [value]="m">{{m}}</option> 

datetest1.json:

[     {"month": "dec"},     {"month": "jan"},     {"month": "feb"},     ...  ] 

use safe navigation operator if value bind passed input or fetched async call:

<option *ngfor="#m of dateattributeslist?.month" [value]="m.month">{{m}}</option> 

[value] supports string values. if have object values use [ngvalue]

<option *ngfor="#m of dateattributeslist" [ngvalue]="m.month">{{m}}</option> 

[ngvalue] works [ngmodel]