//Given 2 arrays, create a function that lets a a user know (true/false) whether
// two arrays contain any common items.
//Example 1:
//const array1 =['a','b','c','x']
//const array2 = ['z','y','i']
//should return false
//--------------------
//const array1 =['a','b','c','x']
//const array2 = ['z','y','x']
//should return true
//function has 2 parameters - arrays
//return true or false
//runtime is O(n*m) n being input size of input1 and m being input size of input 2
//brute force approach
//space complexity is O(1)
const array1 =['a','b','c','x']
const array2 = ['z','y','x']
/*
function containsCommonItem(arr1,arr2)
{
for(let i = 0; i < arr1.length; i++)
{
for(let j = 0; j < arr2.length; j++)
{
if(arr1[i] === arr2[j])
{
return true;
}
}
}
return false;
}
console.log(containsCommonItem(array1,array2));*/
// array1 ==> obj {
// a:true,
// b:true,
// c:true,
// x:true,
//}
// array2[index] == obj.properties
//
function containsCommonItem2(arr1,arr2)
{
//loop through first array and create object where properties === items in array
// loop through second array and check if item in second array exists on
//created object.
//runtime is O(n + m)
//space complexity is O(n)
//can we assume always 2 params
let map = {};
for(let i = 0; i < arr1.length; i++)
{
if(!map[arr1[i]])
{
const item = arr1[i];
map[item] = true;
}
}
for(let j = 0; j < arr2.length; j++)
{
if(map[arr2[j]])
{
return true;
}
}
return false;
}
console.log(containsCommonItem2(array1,array2));
function containsCommonItem3(arr1,arr2)
{
return arr1.some(item => arr2.include(item));
}
//create a function that reverses a string
function reverse(str)
{
let reverse_string = "";
for(let i = str.length -1; i > 0; i--)
{
reverse_string += str[i];
}
return reverse_string;
}
const result = "Philip";
console.log(reverse(result));
