How To Find Validate Email Address format in JavaScript Regex:
const EMAIL_REGEX = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
let email = "m.e@my.email";
alert( EMAIL_REGEX.test(email));
Can you run GTX 1050 TI on 220W Power Supply?
Short Answer: Yes you can.
How to Set proper Rules on Google Firebase DB:
Here is an example of a pretty simple rules setting. We don’t want just anyone to access user information. The users sub directory is restricted to the user logged in. The rest is fully restricted and is only accessible via admin api.
service cloud.firestore {
match /databases/{database}/documents {
// Make sure the uid of the requesting user matches name of the user
// document. The wildcard expression {userId} makes the userId variable
// available in rules.
match /someusercollection/{userID}/{document=**} {
allow read, update, delete: if request.auth.uid == userId;
allow create: if request.auth.uid != null;
}
match /somecollection/{document=**} {
allow read, update, delete, create: if false;
}
}
}
Read more on the Firebase Docs.
const object1 = {
a: '1',
b: 2
};
for (let [key, value] of Object.entries(object1)) {
console.log(key);
console.log(value);
};
function binarySearch (list, value) {
// initial values for start, middle and end
let start = 0
let stop = list.length - 1
let middle = Math.floor((start + stop) / 2)
// While the middle is not what we're looking for and the list does not have a single item
while (list[middle] !== value && start < stop) {
if (value < list[middle]) {
stop = middle - 1
} else {
start = middle + 1
}
// recalculate middle on every iteration
middle = Math.floor((start + stop) / 2)
}
// if the current middle item is what we're looking for return it's index, else return -1
return (list[middle] !== value) ? -1 : middle
}
const list = [2, 5, 8, 9, 13, 45, 67, 99]
console.log(binarySearch(list, 99)) // 7 -> returns the index of the item
How to Implement Merge Sort in JavaScript the easy way.
// Split the array into halves and merge them recursively
function mergeSort (arr) {
if (arr.length === 1) {
// return once we hit an array with a single item
return arr
}
const middle = Math.floor(arr.length / 2) // get the middle item of the array rounded down
const left = arr.slice(0, middle) // items on the left side
const right = arr.slice(middle) // items on the right side
return merge(
mergeSort(left),
mergeSort(right)
)
}
// compare the arrays item by item and return the concatenated result
function merge (left, right) {
let result = []
let indexLeft = 0
let indexRight = 0
while (indexLeft < left.length && indexRight < right.length) {
if (left[indexLeft] < right[indexRight]) {
result.push(left[indexLeft])
indexLeft++
} else {
result.push(right[indexRight])
indexRight++
}
}
return result.concat(left.slice(indexLeft)).concat(right.slice(indexRight))
}
const list = [2, 5, 1, 3, 7, 2, 3, 8, 6, 3];
console.log(mergeSort(list)) // [ 1, 2, 2, 3, 3, 3, 5, 6, 7, 8 ];
function CountingMinutes(str) {
let arr = str.split("-");
// console.log(arr[0]);
// code goes here
let day = 24 * 60;
let end = getMinutes(arr[1]);
let start = getMinutes(arr[0]);
// console.log('end is ' + end);
// console.log('start is ' + start);
if (end < start){
end += day;
}
return (end-start) ;
}
function getMinutes(time){
let hr = parseInt(time.split(':')[0]);
let min = parseInt(time.split(':')[1].match(/[0-9]/g).join(""));
let morning = time.match(/am/g);
let pm = time.match(/pm/g);
// console.log(pm);
if (pm && hr < 12){
hr += 12;
}
else if (morning && hr === 12){ // convert midnight to zero
hr += 12;
}
let totalMin = parseInt((hr*60) + min);
return totalMin ;
}
A common interview question. Here is how to solve it (the easy way).
function isPalindrome(str){
let reverse = str.split("").reverse().join("");
if (reverse === str){
console.log('we got a palindrome!');
return true;
}
return false;
}
let test = "neven";
isPalindrome(test);