11- problem solving

//array [1, 2, 3, 4]
//Target- multiply each element by 2 and return total summation

//breakdown
//receive the input
//map , simple for loop
//[2, 4, 6, 8] multiply by 2
//total summation - reduce

// function multiplyAndSum(arr) {
// let sum = 0
// for(let i = 0; i < arr.length; i++){
//   sum += arr[i] * 2
//   console.log(arr[i] * 2)
// }
//   return arr.map(elm => elm * 2).reduce((a, b) => a + b)
// }

// console.log(multiplyAndSum([1, 2, 3, 4]))

//searching element
// const arr = [1, 2, 3, 4]

// function searchElementIndex(arr, searchElement) {
//   //findIndex, indexOf
//   //plain way
//   let index = -1
//   for (let i = 0; i < arr.length; i++) {
//     if (arr[i] === searchElement) {
//       index = i
//       break
//     }
//   }
//   return index
// }

// console.log(searchElementIndex(arr, 2))

//Write a JavaScript program to create a new string without the first and last character of a given string and string length must be 3 or more
function without_first_end(str) {
  //substr, by index, array and slice
  // if (str.length < 3) return false
  // return str.slice(1,  -2)

  return [...str].slice(1, str.length - 1).join('')
}
console.log(without_first_end('JavaScript')) //avascrip
console.log(without_first_end('JS')) //false
console.log(without_first_end('PHP')) //H

function compare(arr1, arr2) {
  let result = true
  if (arr1.length !== arr2.length) return false
  //solution-1

  //   for(let i = 0; i < arr1.length; i++){
  //     for (let z = 0; z < arr2.length; z++) {
  //       if(arr1[i] !== arr2[z]){
  //         result = false
  //         break
  //       }
  //     }
  //   }

  //solution-2
  // return arr1.toString() === arr2.toString()

  //solution-3
  for (let i = 0; i < arr1.length; i++) {
    if (arr1[i] !== arr2[i]) {
      result = false
      break
    }
  }
  return result
}

console.log(compare([1, 2, 3], [1, 2, 3])) //true
console.log(compare([1, 2, 3], [2, 2, 3])) //false
console.log(compare([1, 2, 3], [1, 2, 3, 4])) //false