Question

我想删除与Firebase相关的localStorage。我试过这个：

  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
  }

然而，它们根本没有被删除。

我做错了什么？

Answer 1

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

这永远不会成真。你得到一个长3个字符的字符串，并将其与“firebase：”进行比较。只需将3更改为9即可，如下所示：

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

Answer 2

您不需要使用任何额外的数组和循环。

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

Answer 3

<强> JS

你必须指定subtrig共9个charatcers从0开始

 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)

如何从某个字符串开始删除localStorage数据？

3 个答案: