Why Ramdajs.filter() works in my code and Ramdajs.find() not?

Question

I have a js object like

var storage = [
1:{"index":1, "label": abc, "value": 33},
2:{"index":2, "label": def, "value": 43},
etc.
];

so, now i need to extract a given inner object given a "label" value

i find working:

R.filter( R.propEq( "label", labelname ), storage )

but find() isn't working:

R.find( R.propEq( 'label', labelname ))( storage )

can anybody enlighten me about this?

score 1 · Accepted Answer · answered Jan 19 '16 at 19:05

1

I'm a little confused by your data structure. Doing it like this, both filter and find seems to work fine:

var abc = "ABC", def = "DEF";

var storage = [
  {"index":1, "label": abc, "value": 33},
  {"index":2, "label": def, "value": 43},
  {"index":1, "label": abc, "value": 53},
];

var labelname = abc;

R.filter( R.propEq( "label", labelname ), storage );
//=> [{"index":1,"label":"ABC","value":33},{"index":1,"label":"ABC","value":53}]
R.find( R.propEq( "label", labelname ), storage );
//=> {"index":1,"label":"ABC","value":33}

You can see this in action on the Ramda REPL.

What are those extra index numbers in the beginning of your records?:

var storage = [
1:{"index":1, "label": abc, "value": 33},
^
 \---- What's this?

answered Jan 19 '16 at 19:05

Scott Sauyet

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that is an index. i save my objects in a json array due i use localStorage. – leandro713 Jan 20 '16 at 15:14
So it's an object, not an array? I was confused by the square brackets. – Scott Sauyet Jan 20 '16 at 16:08
1

`find` does not work on Objects. `find` on lists returns the first matching value, but the notion of "first" on an object is a bit slippery. – Scott Sauyet Jan 20 '16 at 18:18
it's the index, because i save my data in localStorage as an array converted to JSON – leandro713 Jan 20 '16 at 18:26
1

I was just trying to understand the structure when it's used in JS. `[1: {}, 2: {}]` is not legal syntax. `[{}, {}]` and `{1: {}, 2: {}}` are both fine. – Scott Sauyet Jan 20 '16 at 18:50

Why Ramdajs.filter() works in my code and Ramdajs.find() not?

1 Answers1