javascript - Undefined key coming -
below code:
var xx=[]; xx['1'] ={'a':'bb','c':'dd'} debugger; document.log(xx);
when print xx says undefined key
https://jsfiddle.net/kjuhpgn2/
can let me know why "undefined" coming instead of "1" key?
edit:
i got that, should {} instead of []
var xx={};
array indexing start @ 0
.
what it's saying have nothing @ index 0
.
when set xx[1]=something
starting array of size 0
, set length of array 2
, @ index 1 , undefined
"filling" position @ index 0.
if want store dictionary, don't use array object map:
var xx={}; xx['1'] ={'a':'bb','c':'dd'}
this way wouldn't create sparse array.
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