masautt

function hasDuplicates(array) {
    return (new Set(array)).size !== array.length;
}

console.log(hasDuplicates(["M", "A", "S", "A", "U", "T", "T"])); // --> true
console.log(hasDuplicates(["M", "A", "R", "E", "K"])); // --> false

// https://stackoverflow.com/questions/7376598/in-javascript-how-do-i-check-if-an-array-has-duplicate-values

masautt

console.log(["M", "A", "R", "E", "K"].includes("R")); // --> true

console.log(["M", "A", "R", "E", "K"].includes("S")); // --> false

masautt

// Using Sets
function removeDupes(arr) {
  return [...new Set(arr)];
}

// Using filter( )
function removeDupes1(arr) {
  return arr.filter((v,i) => arr.indexOf(v) === i)
}

masautt

var longestPalindrome = function(s) {
    if (isPalindrome(s)) {
        return s;
    }
    
    var maxP = s[0];
    
    for (var i=0; i < s.length; i++) {
        var curr = s[i];
        for (var j= i + 1; j < s.length; j++) {

masautt

String.prototype.count=function(s1) { 
    return (this.length - this.replace(new RegExp(s1,"g"), '').length) / s1.length;
}

console.log("Marek Sautter".count("e")); // --> 2

console.log("I got a letter from Marek Sautter".count("tt")); // --> 2

// https://stackoverflow.com/questions/881085/count-the-number-of-occurrences-of-a-character-in-a-string-in-javascript

masautt

function getLetters(words) {
  var words      = (typeof words == 'string') ? words : '',
      count      = re => (words.match(re) || []).length,
      vowels     = count(/[aeiou]/ig),
      consonants = count(/[bcdfghjklmnpqrstvxzwy]/ig);

  return {vowels, consonants};
}

console.log(getLetters("Marek Sautter")); // --> { vowels: 5, consonants: 7 }

masautt

function checkNum(str) {
  return /^\d+$/.test(str)
}
console.log(checkNum("8675309")); // --> true
console.log(checkNum("867S309")); // --> false

// https://stackoverflow.com/questions/1779013/check-if-string-contains-only-digits

masautt

let num = 8675309
console.log(num.toString()) // --> "8675309"

masautt

console.log(parseInt("8675309 hmu :)")) // --> 8675309

console.log(parseFloat("3.14 is PI")) // --> 3.14

// https://gomakethings.com/converting-strings-to-numbers-with-vanilla-javascript/

masautt

function isAnagram (a, b) {
    var y = a.split("").sort().join(""),
        z = b.split("").sort().join("");
    return (z === y)
}

console.log(isAnagram("marek", "kemra")) // --> true
console.log(isAnagram("sautter", "sautrra")) // --> false

// https://stackoverflow.com/questions/23785465/javascript-anagram-comparison