Verify the presence of a JSON object within the session storage using JavaScript

I'm currently developing a website where some data is stored within the session. In the initial page, I need to verify if the JSON object already exists in the session. Below is the code snippet that's causing issues:

 var passedTotal = JSON.parse(sessionStorage.getItem('test total array'));
 if(passedTotal.hasOwnProperty('letterplaatnaam')){
 //do something
 }

If the JSON object exists, everything works fine. But if it doesn't exist, the following error occurs:

Uncaught TypeError: Cannot read property 'hasOwnProperty' of null

I understand that this error is due to the object being empty. I've searched through various Stack Overflow questions but haven't found a solution yet. If you need more information, feel free to ask.

javascriptjsonsessionsession-variables

Answer №1

Consider:

if(passedTotaal!==null && passedTotaal.hasOwnProperty('letterplaatnaam'))

Answer №2

const retrieveTest = sessionStorage.getItem('test total array');
if (retrieveTest) {
    const parsedTest = JSON.parse(retrieveTest);
    if(parsedTest && parsedTest.hasOwnProperty('letterplate name')){
        //perform an action
    }
}

since getItem may also return null

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