CODEWITHSUNDEEP
javascripthtmllocal-storage
Trishul
Trishul

Reputation: 1028

Clear localstorage values with certain prefix

I have stored several key value pairs which contains certain encrypted login information using HTML5 localstorage variables. I have added a unique prefix to all key names say TM_loginname . Now I want to clear all the localstorage key-value pairs whose key starts with prefix TM_. PS: I tried sessionstorage too, but it clears only when browser is closed.

Upvotes: 43

Views: 27791

Answers (6)

tbenst
tbenst

Reputation: 1050

A more modern (ES2017) solution is as follows:

Object.entries(localStorage).map(
        x => x[0] # get keys
    ).filter(
        x => x.substring(0,3)=="TM_"
    ).map(
        x => localStorage.removeItem(x))

EDIT

Taken from the comments:

Object.keys(localStorage)
 .filter(x =>
    x.startsWith('TM_'))
 .forEach(x => 
    localStorage.removeItem(x))

Upvotes: 22

Nuno Ribeiro
Nuno Ribeiro

Reputation: 2565

Adapting the tip of github:

findLocalItems(query) {
var i,
  results = [];
for (i in localStorage) {
  if (localStorage.hasOwnProperty(i)) {
    if (i.match(query) || (!query && typeof i === 'string')) {
      var value = JSON.parse(localStorage.getItem(i));
      results.push({ key: i, val: value });
    }
  }
}
return results;  }

And after, calling the function:

var keysFounded = findLocalItems(key);
if (keysFounded && keysFounded.length > 0) {
  keysFounded.forEach(k => {
    localStorage.removeItem(k.key);
  });
}

Upvotes: 1

Omu
Omu

Reputation: 71288

save to localStorage using key = pref + version

function remLSPref(pref, newName) {
    for (var key in localStorage) {
        if (key.indexOf(pref) == 0) {
            if (key != newName) {
                localStorage.removeItem(key);
            }
        }
    }
}

and use like this:

var pref = 'myid_';
var key = pref + ver;

// rem old ls
remLSPref(pref, key);

Upvotes: 4

Diego Laciar
Diego Laciar

Reputation: 3302

Using lodash. Enjoy.

_.forIn(window.localStorage, (value: string, objKey: string) => {
    if (true === _.startsWith(objKey, 'TM_')) {
        window.localStorage.removeItem(objKey);
    }
});

Upvotes: 11

RonyHe
RonyHe

Reputation: 942

Removing element while iterating is unsafe, so create an array to hold the keys that need to be removed. Then, iterate over that array to remove them:

var arr = []; // Array to hold the keys
// Iterate over localStorage and insert the keys that meet the condition into arr
for (var i = 0; i < localStorage.length; i++){
    if (localStorage.key(i).substring(0,3) == 'TM_') {
        arr.push(localStorage.key(i));
    }
}

// Iterate over arr and remove the items by key
for (var i = 0; i < arr.length; i++) {
    localStorage.removeItem(arr[i]);
}

Upvotes: 61

Etheryte
Etheryte

Reputation: 25321

You can either:

Upvotes: 1

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