Why stringified objects differs from the original

Question

There is such local function (in functional component with state provided useState hook) that has a deal with the state

      let setContainer = container => {
        let newState = {...state, files: deleteAllFromTo(state.files), container}
        let newStateIntermediate = JSON.parse(JSON.stringify(newState))
    
        console.log('-----------------')
        console.log(newState)
        console.log(newStateIntermediate)
        setState(newStateIntermediate)
      }

Why the newState and newStateIntermediate are able to be different?

Does this answer your question? [Is Chrome's JavaScript console lazy about evaluating arrays?](https://stackoverflow.com/questions/4057440/is-chromes-javascript-console-lazy-about-evaluating-arrays) — ASDFGerte, Jul 19 '20 at 15:53

score 0 · Answer 1 · answered Jul 19 '20 at 16:18

0

Don't rely on console.log to test deep equality. As ASDFGerte and this question have pointed, it might be lazy. Use, for instance, lodash.isEqual for that. If it happens to return false, then inspect the objects.

answered Jul 19 '20 at 16:18

Rodrigo Amaral

1,324
1
13
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score 0 · Answer 2 · answered Jul 19 '20 at 16:49

0

Thank you everyone for your sugestions. The problem was that in the first case 'to' is a property of the audio object, but in the second one 'to' is a property of audio[0].

answered Jul 19 '20 at 16:49

misterx527

97
5

Why stringified objects differs from the original

2 Answers2