Test Answers for ITWal

Test Answers

Question 1
indexOf returns the integer value 
and when you attach ! with it it returns true 
so instead of checking for true or false we can 
check the integers
function myFunction() {
var str="Superman OS running";
    if (str.toLowerCase().indexOf('superman') == -1) {
        console.log('String does not contain superman');
    }    

}


Question 2 
functions Search(searchvalue)
{
 var arr=[1,2,3,4,5];
 for(var i=0;i<arr.length;i++)
 {
 
  if(searchvalue==arr[i])
  {
   return true;
  }
 }
 
 return false;

}


Question 3
const formatPhone = (str, delimiter = '-') => {
	str = str.trim()
	let phone = ''

	for(let n of str){
	  if(n === ' ' || isNaN(+n)){
	    continue
	  }
	  
	  phone += n
	}

	if(!phone || phone.length !== 10){
		throw Error(`Invalid phone number ${str}`)	
	}

	return phone.substr(0, 3)
	    + delimiter
	    + phone.substr(3, 3)
	    + delimiter
	    + phone.substr(0, 4);
};



Question 4
  it('should return valid for index 1')
  it('should return valid for index 2')
  it('should return valid for index 3')
  it('should return valid for index 4')
  it('should return valid for index 5')
  it('should return valid for index 14')
  it('should return valid for index 15')
  it('should return valid count of symbols for 100')

Question 5
function filterFiles(items, ignore) {
	const lenItems = items.length;
	const lenIgnore = ignore.length;

	let c = 0;
	let output = [];

	for (let i = 0; i < lenItems; i++) {
		let j = 0;
		let k = 0;

		while (
			ignore[j] !== items[i] &&
			items[i].indexOf(ignore[j]) !== 0 &&
			j < lenIgnore
		) {
			j++;
		}

		while (output[k] !== items[i] && k < c) {
			k++;
		}

		if (j == lenIgnore && k == c) {
			output[c++] = items[i];
		}
	}

	return output;
}


Question 6 
Couldnt understand the question

Question 7 
You clicked button #0
You clicked button #3
//Because the index is starting from 0


Question 8 
const isIterable = (obj) => {
  try {
  	return typeof obj[Symbol.iterator] === 'function'
  }catch(e){
  	return false
  }
}