arrays - Javascript: How do I create a function that can generate an X amount of objects drawing from fixed amount of classes? -

-

for coding assignment, i'm tasked creating function can generate x amount of objects drawing fixed amount of classes. while objects being generated, store objects in array. how go doing in javascript?

pretty same 2 objects. use length of array pick random element, , use loop perform action x times:

/* class definitions */  function animal(){ var = document.createelement('div'); a.classname = 'animal'; return a}  function horse(){ var = new animal(); a.classname += ' horse'; return }  function pig(){ var = new animal(); a.classname += ' pig'; return }  function rat(){ var = new animal(); a.classname += ' rat'; return }    /* variable definitions */  var animals = ['horse', 'pig', 'rat'],      output = document.getelementbyid('output'),      numberofdraws = 5,      res = [];    /* auxiliary functions */  // returns random element given array  function pickrandom(arr){      return arr[ math.floor( math.random()*arr.length ) ];  }    /* main script */  // pick random object 5 times, store in 'res' , show  for(var = 0; < numberofdraws; i++){    res.push( eval('new ' + pickrandom(animals) + '()') );    output.appendchild( res[i] );  }
.animal{float:left;padding:40px;background-size:100%}.horse{background-image:url(https://pbs.twimg.com/profile_images/587037647966613504/mk5oeksb.png)}.pig{background-image:url(https://33.media.tumblr.com/avatar_c2b180faa484_128.png)}.rat{background-image:url(http://38.media.tumblr.com/avatar_614c66cef635_128.png)}
<pre id="output"></pre>

edit: instance of class, can eval class name. see demo above.


Comments

Post a Comment

Popular posts from this blog

PHP DOM loadHTML() method unusual warning -

-
i had following code works fine on localhost: $document = new domdocument(); $document->loadhtml($p_result); $form = $document->getelementsbytagname('form')->item(0); // code continues using $form variable after same code updated on outside server, loadhtml() failed , issued warning. warning: domdocument::loadhtml() expects parameter 1 valid path, string given in path/name/to/script.php returned null instead of object code pretty gets fatal error. note contents of $p_result absolutely same on outside server , on localhost. but why displays kind of warning , why not work? doesn't loadhtml() expects argument 1 string in first place? why method expects parameter 1 valid path ? just make clear i'm not calling loadhtmlfile() , i'm calling loadhtml() . thanks. you're affected one of php bugs . issue present in php 5.6.8 , 5.6.9. have affected php version on server, , bug-free version on localhost. the bug forbids null
Read more

python - How to create jsonb index using GIN on SQLAlchemy? -

-
here's current code creating index jsonb. index("mytable_data_idx_id_key", mytable.data['id'].astext, postgresql_using='gin') but got error. sqlalchemy.exc.programmingerror: (psycopg2.programmingerror) data type text has no default operator class access method "gin" hint: must specify operator class index or define default operator class data type. [sql: "create index event_data_idx_id_key on event using gin ((data ->> 'id'))"] is there way create index on sqlalchemy? the postgresql specific sqlalchemy docs @ http://docs.sqlalchemy.org/en/latest/dialects/postgresql.html#operator-classes mention postgresql_ops dictionary provide "operator class" used postgresql, , provide example illustrating use: index('my_index', my_table.c.id, my_table.c.data, postgresql_ops={ 'data': 'text_pattern_ops',
Read more

c# - TransactionScope not rolling back although no complete() is called -

-
i'm using transactionscope rollback transaction fail bool errorreported = false; action<importerrorlog> newerrorcallback = e => { errorreported = true; errorcallback(e); }; using (var transaction = new transactionscope()) { foreach (importtaskdefinition task in taskdefinition) { loader.load(streamfile, newerrorcallback, task.destinationtable, processingtaskid); } if (!errorreported) transaction.complete(); } i'm sure there no transactionscope started ahead or after code. i'm using entity framework insert in db. regardless state of errorreported transaction never rolled in case of error. what missing ? transactionscope sets transaction.current . that's does. wants transacted must @ property. i believe ef each time connection opened reason. probably, connection open when scope installed. open connection inside of scope or enlist manually. ef has nasty "design decision": default opens
Read more