JAVASCRIPT

js check if string includes from array

wordsArray = ['hello', 'to', 'nice', 'day']
yourString = 'Hello. Today is a nice day'.toLowerCase()
result = wordsArray.every(w => yourString.includes(w))
console.log('result:', result)

js check if string includes from array

const found = arrayOfStrings.find(v => str.includes(v));

Check if an array contains a string in javascript

const colors = ['red', 'green', 'blue'];
const result = colors.includes('red');

console.log(result); // true

js check if array contains value

var arr = ["name", "id"];
  if (arr.indexOf("name") > -1) console.log('yeah');
  else console.log('nah');

How do I check if an array includes a value in JavaScript?

Modern browsers have Array#includes, which does exactly that and is widely supported by everyone except IE:

console.log(['joe', 'jane', 'mary'].includes('jane')); //true

check if array does not contain string js

function checkInput(input, words) {
 return words.some(word => input.toLowerCase().includes(word.toLowerCase()));
}

console.log(checkInput('"Definitely," he said in a matter-of-fact tone.', 
["matter", "definitely"]));

javascript check if in array

var extensions = ["image/jpeg","image/png","image/gif"];          
if(extensions.indexOf("myfiletype") === -1){
	alert("Image must be .png, .jpg or .gif");
} 

how to check if array contains an item javascript

let isInArray = arr.includes(valueToFind[, fromIndex])
// arr         - array we're inspecting
// valueToFind - value we're looking for
// fromIndex   - index from which the seach will start (defaults to 0 if left out)
// isInArray   - boolean value which tells us if arr contains valueToFind

How to Check if an Item is in an Array in JavaScript Using Array.includes()

const nums = [ 1, 3, 5, 7];
console.log(nums.includes(3));
// true

js check if array contains value

return arrValues.indexOf('Sam') > -1

if array includes string

function droids(arr) {
  let result = 'These are not the droids you're looking for';
  for(let i=0; i<arr.length;i++) {
      if (arr[i] === 'Droids') {
      result = 'Found Droid';
    }
  }
  return result;
}

// Uncomment these to check your work! 
const starWars = ["Luke", "Finn", "Rey", "Kylo", "Droids"]
const thrones = ["Jon", "Danny", "Tyrion", "The Mountain", "Cersei"]
console.log(droids(starWars)) // should log: "Found Droids!"
console.log(droids(thrones)) // should log: "These are not the droi





//A simpler approach 

console.log(starWars.includes('Droids') ? 'Droid Found' : 'These are not the droids you're looking for');
console.log(thrones.includes('Droids') ? 'Droid Found' : 'These are not the droids you're looking for');

check if array does not contain string js

function checkInput(input, words) {
 return words.some(word => new RegExp(word, "i").test(input));
}

console.log(checkInput('"Definitely," he said in a matter-of-fact tone.', 
["matter", "definitely"]));

js array string includes

if (new RegExp(substrings.join("|")).test(string)) {
    // At least one match
}

javascript check if array is in array

var array = [1, 3],
    prizes = [[1, 3], [1, 4]],
    includes = prizes.some(a => array.every((v, i) => v === a[i]));

console.log(includes);

js check if string includes from array

function buildSearch(substrings) {
  return new RegExp(
    substrings
    .map(function (s) {return s.replace(/[.*+?^${}()|[]]/g, '$&');})
    .join('{1,}|') + '{1,}'
  );
}


var pattern = buildSearch(['hello','world']);

console.log(pattern.test('hello there'));
console.log(pattern.test('what a wonderful world'));
console.log(pattern.test('my name is ...'));

if Array includes string

function droids(arr) {
    result = "These are not the droids you're looking for." 
    
    for (str of arr) {
        if (str == 'Droids')
            result = "Found Droids!"
    }
    
    return result;
}

javascript - Determine whether an array contains a value

var contains = function(needle) {
    // Per spec, the way to identify NaN is that it is not equal to itself
    var findNaN = needle !== needle;
    var indexOf;

    if(!findNaN && typeof Array.prototype.indexOf === 'function') {
        indexOf = Array.prototype.indexOf;
    } else {
        indexOf = function(needle) {
            var i = -1, index = -1;

            for(i = 0; i < this.length; i++) {
                var item = this[i];

                if((findNaN && item !== item) || item === needle) {
                    index = i;
                    break;
                }
            }

            return index;
        };
    }

    return indexOf.call(this, needle) > -1;
};