window.reload = () => {
var userArray = JSON.parse(localStorage.getItem("key"));
}
let feedback = document.getElementById("feedback");
function checkemail(userArray, email) {
var i;
if (userArray == null | undefined) {
userArray = JSON.parse(localStorage.getItem("key"));
}
var person = {
name: document.getElementById("nameinput").value,
email: document.getElementById("emailinput").value,
passowrd: document.getElementById("passwordinput").value
};
let isFound = false;
for (i = 0; i < userArray.length; i++) { //here is the error it still happen even after I added the if null part
if (userArray != undefined)
var oldemail = userArray[i].email;
let newemail = document.getElementById("emailinput").value;
if (newemail === oldemail) {
isFound = true;
i = userArray.length;
return feedback.innerHTML = "email exist please log in or register with different email";
}
}
if (!isFound) {
return storeName(person, userArray);
}
}
function storeName(person, userArray) {
if (userArray != undefined)
var person = {
name: document.getElementById("nameinput").value,
email: document.getElementById("emailinput").value,
passowrd: document.getElementById("passwordinput").value
};
userArray = JSON.parse(localStorage.getItem("key"));
userArray.push(person);
userArray = JSON.stringify(userArray);
localStorage.setItem("key", userArray);
console.log(userArray);
}I want to store an array in local storage, the first time when I run the code, of course, the array is empty and I can not use a loop for example because I can't call (array.length). so can I tell the compiler for example if the array is null or undefined just put length is zero or assign the value of the array to an empty array?
can I do something like this?
if( userArray == null | undefined) { userArray = JSON.parse(localStorage.getItem("key")); }
function checkemail(userArray, email) {
if (userArray == null || typeof(userArray) == 'undefined') {
userArray = [];
}
// rest of the code
}
This might be working too:
userArray ??= [];