Javascript Index of for Multiple Values

How to get indexOf to check for one or multiple values

One option is to use a regular expression instead:

/Word1|Word2|Word3/.test(string)

Or iterate over an array of words to search for:

var found = false;
var arr = ['Word1', 'Word2', 'Word3']
for (var i = 0; i < arr.length; i++) {
  if (string.indexOf(arr[i]) !== -1) {
    found = true;
    break;
  }
}
// use `found` variable

If you want to ensure that the string doesn't contain any of those words with a regex, then continually match characters from the beginning of the string to the end while using negative lookahead for the alternated pattern:

^(?:(?!Word1|Word2|Word3)[\s\S])+$

https://regex101.com/r/FsChvB/1

But that's strange, it'd be a lot easier just to use the same test as above, and invert it.

var stringContainsForbiddenWords = !/Word1|Word2|Word3/.test(string)

indexOf with multiple arguments

The || operator returns the left hand side if it is true, otherwise it returns the right hand side. 123 || 124 || 125 just means 123.

If you want to test if any of multiple values are in an array, then you have to test each one in turn.

array.indexOf(123) == 0 || array.indexOf(124) == 0 || array.indexOf(125) == 0

Since you only care about one specific index the array, you can turn the whole thing on its head:

[123, 124, 125].indexOf(array[0]) > -1

Javascript index of for multiple values

You can use the .filter() method:

var mainArray = [ /* your array here */ ],
    check = ["15", "21"],
    result;

result = mainArray.filter(function(val) {
    for (var i = 0; i < check.length; i++)
        if (val.indexOf(check[i]) === -1)
            return false;    
    return true;
});

console.log(result);

Demo: http://jsfiddle.net/nnnnnn/Dq6YR/

Note that .filter() is not supported by IE until version 9, but you can fix that.

How to find index of object in array using multiple values with ES5?

ES6+

You can use .findIndex()

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex

var found = items.findIndex(function(itm) {
   return itm.number1 === number1 && itm.number2 === number2;
});

ES5:

Using .filter():

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

var foundItems = items.filter(function(itm) {
   return itm.number1 === number1 && itm.number2 === number2;
});

if (foundItems && foundItems.length > 0) {
 var itemYouWant = foundItems[0];
}

Getting the index--you can have the index value returned as part of the filter method. Check out the docs for more examples.

How to get multiple indexes of array by a value in pure JavaScript (value exact matching)

You can reduce the array to array of indexes, which value is 1:

const arr = [1, 11, 1, 111, 1111, 11, 1, 1111, 11];
const indexes = arr.reduce((r, n, i) => {  n === 1 && r.push(i);    return r;}, []);
console.log(indexes);

Getting the index of a value having multiple positions in an array

Returning result.push cuts your iteration short, and doesn't even include the index. Instead check if each element is equal to the needle, and then push the index if it's equal.

function indexOfValue(needle, hayStack) {    let result = [];    for(let i = 0; i < hayStack.length; i++) {        if (hayStack[i] === needle) { // check if matching            result.push(i); //push the index        }    } return result; //return result at end}console.log(indexOfValue(12, [12, 1, 3, 3, 6, 12]))

How to get a value from multiple arrays by the index?

You can use Array#map to get a new array containing the fifth elements of each inner array. Note that arrays are zero-indexed, so the fifth value is at index 4.

const BOARD = [            
    [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'],
    [ '5', '5', '5', '5', '5', '9', 'B', 'B', 'C', 'D', 'E', 'F', 'F', '1', '2', '3'],
    [ '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7'],
    [ 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B'],
    [ '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0'],
    [ '5', 'A', 'A', 'A', 'A', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4'],
    [ '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8'],
    [ 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C'],
    [ '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1'],
    [ '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5'],
    [ 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'],
    [ 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D'],
    [ '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2'],
    [ '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6'],
    [ 'B', 'C', 'D', 'E', 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A'],
    [ 'F', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E'],
];
let res = BOARD.map(r => r[4]);
console.log(res);