如何从某个字符串开始删除localStorage数据？

Question

I want to remove Firebase-related localStorage. I tried this:

  let arr = [] // Array to hold the keys
  // Iterate over localStorage and insert the keys that meet the condition into arr
  for (let i = 0; i < localStorage.length; i++) { // eslint-disable-line
    console.log(localStorage.key(i)) // eslint-disable-line
    if (localStorage.key(i).substring(0,3) == 'firebase:') { // eslint-disable-line
      arr.push(localStorage.key(i)) // eslint-disable-line
    }
  }
  // Iterate over arr and remove the items by key
  for (let i = 0; i < arr.length; i++) {
    localStorage.removeItem(arr[i]) // eslint-disable-line
  }

However they are not being removed at all.

What am I doing wrong?

Answer 1

substring(0,3) == 'firebase:'

This can never be true. You're getting a string 3 characters long and comparing it to "firebase:". Just change your 3 to a 9 so it looks like this:

substring(0, 9) == 'firebase:'

Answer 2

You don't need to use any extra array and a loop.

for (key in localStorage) {
  if (key.substring(0,9) == 'firebase:') {
    localStorage.removeItem(key);
  }
}

Answer 3

JS

u have to specify the substrig totally 9 charatcers starts with 0

 localStorage.setItem("abc" , "heelo");
       localStorage.setItem("abc2" , "firebase:")
        for (obj in localStorage) {
      if (localStorage[obj].substring(0,9) == 'firebase:') {
        localStorage.removeItem(obj);
      }
    }
    console.log(localStorage)