Determine the presence of a particular set of values within an array of named objects stored in the browser's localStorage using JavaScript

Question

Determine the presence of a particular set of values within an array of named objects stored in the browser's localStorage using JavaScript

Previously, I stored various objects in localStorage in the following format:

console.log(localStorage) 
// The storage output may vary, with different objects (such as randid)

Storage {
    876346545: "{"ABA":"876346545","ABB":"37578533567","ABC":"AE123456","ABD":"1234567890123456"}", 
    randid: "fhjidc06om230j2r367gh1i5iec", 
    353446545: "{"ABA":"353446545","ΑBB":"12343212341","ΑBC":"CC949590","ABD":"5943949562340543"}", 
    length: 3
}

I am attempting to check if a specific pair exists within this array of objects.

 //Pseudo-code
 if anyofObject in localStorage contains pair ("ABA":"876346545") return true or false

The code I'm using isn't behaving as expected

var data = JSON.parse(localStorage) // I've also tried without parsing it as JSON

for (var key in data) {
    if (data[key].ABA = "876346545") {
        var m = data[key];
        console.log("Found: ", m)
        break;
    }
}

javascript arrays json local-storage

Answer 1

Answer №1

If you wish to iterate through all the values stored in your local storage, follow these steps:

Retrieve all values using Object.values and filter them one by one
Attempt to convert them into JSON objects; those that fail are not of interest
For successfully parsed values, check if the key matches both in type and value. Once a match is found, return true to complete the search and store the value in a variable.

Remember to use === for value comparisons, not =, as depicted in the question. Pay attention to data types when making comparisons; for instance, setting ABA as a number but trying to compare it with a string.

userData = {
  "ABA": 876346545, 
  "ABB": 37578533567, 
  "ABC": "AE123456", 
  "ABD": 1234567890123456
};

localStorage.setItem("Some Random Key", JSON.stringify(userData));

// Find the object and store it in foundObject variable
const foundObject = Object.values(localStorage).find(v => { 
  try { 
    return JSON.parse(v).ABA === 876346545; 
  } catch(e) {
    return false;
  };
});

console.log(JSON.stringify(foundObject));

// Find the object and store true if found, false if not found in hasObject variable
const hasObject = Object.values(localStorage).some(v => { 
  try { 
    return JSON.parse(v).ABA === 876346545; 
  } catch(e) {
    return false;
  };
});

console.log(JSON.stringify(hasObject));

Answer 2

If you wish to iterate through all the values stored in your local storage, follow these steps:

Retrieve all values using Object.values and filter them one by one
Attempt to convert them into JSON objects; those that fail are not of interest
For successfully parsed values, check if the key matches both in type and value. Once a match is found, return true to complete the search and store the value in a variable.

Remember to use === for value comparisons, not =, as depicted in the question. Pay attention to data types when making comparisons; for instance, setting ABA as a number but trying to compare it with a string.

userData = {
  "ABA": 876346545, 
  "ABB": 37578533567, 
  "ABC": "AE123456", 
  "ABD": 1234567890123456
};

localStorage.setItem("Some Random Key", JSON.stringify(userData));

// Find the object and store it in foundObject variable
const foundObject = Object.values(localStorage).find(v => { 
  try { 
    return JSON.parse(v).ABA === 876346545; 
  } catch(e) {
    return false;
  };
});

console.log(JSON.stringify(foundObject));

// Find the object and store true if found, false if not found in hasObject variable
const hasObject = Object.values(localStorage).some(v => { 
  try { 
    return JSON.parse(v).ABA === 876346545; 
  } catch(e) {
    return false;
  };
});

console.log(JSON.stringify(hasObject));

Answer 3

Answer №2

To access the information stored in localStorage, you will need to parse the object as it is saved as a string.

for (let item in localStorage) {
  try {
    const data = JSON.parse(localStorage[item]);
    if (data.id === "876346545") {
       let result = localStorage[item];
       console.log("Located Data: ", result)
       break;
    }
  } catch(error) {
    continue;
  }
}

Answer 4

To access the information stored in localStorage, you will need to parse the object as it is saved as a string.

for (let item in localStorage) {
  try {
    const data = JSON.parse(localStorage[item]);
    if (data.id === "876346545") {
       let result = localStorage[item];
       console.log("Located Data: ", result)
       break;
    }
  } catch(error) {
    continue;
  }
}

Determine the presence of a particular set of values within an array of named objects stored in the browser's localStorage using JavaScript

Answer №1

Answer №2

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