Question

193

How to check key exist in json or not

rated 0 times [ 198] [ 5] / answers: 1 / hits: 93156 / 8 Years ago, wed, august 24, 2016, 12:00:00

I have JSON object and i want to check key is set in that JSON object

Here is JSON object

var Data_Array = {

    Private: {

        Price: {

            Adult: 18,

            Child: [{

                FromAge: 0,

                ToAge: 12,

                Price: 10

            }]

        }

    }

}

If JSON Object like this as you can see Child is not exist, then how to check this

var Data_Array = {

    Private: {

        Price: {

            Adult: 18

        }

    }

}

I have tried

if(Data_Array.Private.Price.Child[0].Price != undefined){

    ...

}

But it is showing me this error

Uncaught TypeError: Cannot read property

I am not be able to find out what should i do.

Answers

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victorw

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3 Years ago

answered 8 Years ago dylondaytond · Accepted Answer

var json = {key1: 'value1', key2: 'value2'}



key1 in json ? console.log('key exists') : console.log('unknown key')



key3 in json ? console.log('key exists') : console.log('unknown key')

for child key

var Data_Array = {

    Private: {

        Price: {

            Adult: 18,

            Child: [{

                FromAge: 0,

                ToAge: 12,

                Price: 10

            }]

        }

    }

}



'Child' in Data_Array.Private.Price ? console.log('Child detected') : console.log('Child missing')

create variable child

var Data_Array = {

    Private: {

        Price: {

            Adult: 18,

            Child: [{

                FromAge: 0,

                ToAge: 12,

                Price: 10

            }]

        }

    }

}



var child = 'Child' in Data_Array.Private.Price && Data_Array.Private.Price.Child[0] || 'there is no child'



console.log(child)

if there is no child

var Data_Array = {

    Private: {

        Price: {

            Adult: 18

        }

    }

}



var child = 'Child' in Data_Array.Private.Price && Data_Array.Private.Price.Child[0] || 'there is no child'



console.log(child)