Why doesn't JSON.stringify() stringify my object as intended?

Question

I'm making a fetch request from react-native. Why will A send the body data correctly, but B come back as undefined?

    let usrn = 'ususus'
    lew pwrd = 'pwpwpw'

    let bodyData = {
        'u': usrn,
        'p': pwrd,
    }

Specifically the body data with JSON.stringify()?

=> A
    return fetch(url, {
            method: "POST",
            headers: headers,
            body: JSON.stringify({
                'u': usrn,    // <= can return this value on server
                'p': pwrd,    // <= can return this value on server
            })
        })

=> B
    return fetch(url, {
            method: "POST",
            headers: headers,
            body: JSON.stringify({ bodyData }) // <= returns undefined on server
        })

Xiaoy312 · Accepted Answer · 2017-11-22 23:54:36Z

10

bodyData is an object, you don't need to wrap it with curly brackets again:

body: JSON.stringify(bodyData);

answered Nov 22, 2017 at 23:54

Xiaoy312

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4 Comments

denden Over a year ago

Thanks, I thought this was it but I could get it to work.

Kenry Sanchez Over a year ago

when I saw the question, my mind starts to think about the us undefined xD but, yeah you're right

Xiaoy312 Over a year ago

There is two problems in your second approach, the {} and also what @Kenry mentioned. So you will have to fix that as well

denden Over a year ago

Thanks to both of you typo fixed.

Kenry Sanchez · Accepted Answer · 2017-11-22 23:55:21Z

2

variable us is not defined..

let bodyData = {
    'u': us,
    'p': pwrd,
}

In the code:

return fetch(url, {
        method: "POST",
        headers: headers,
        body: JSON.stringify({
            'u': usrn,    // <= can return this value on server
            'p': pwrd,    // <= can return this value on server
        })
    })

you are using the property 'u' the variable usrn. it is defined

Change bodyData to..

let bodyData = {
'u': usrn,
'p': pwrd,

}

answered Nov 22, 2017 at 23:55

Kenry Sanchez

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1 Comment

Kenry Sanchez Over a year ago

body: JSON.stringify(bodyData);. Yes, but this is the right answer. the guy has right

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