Javascript Array Dilemmas

Question

Javascript Array Dilemmas

The current task;

Determine whether the first string in the array contains all the letters of the second string.

For instance, ['hello', 'Hello'] should result in true as all letters from the second string are found in the first, regardless of case.

If we consider ['hello', 'hey'], the answer would be false due to the absence of the letter 'y' in 'hello'.

Lastly, looking at ['Alien', 'line'], the expected outcome is true as every letter in 'line' is present in 'Alien'.

Here's a code snippet I've tried that isn't giving the desired result;

function mutation(arr) {
  if (arr[0].toLowerCase().indexOf(arr[1].toLowerCase()) >= 0){
    return true;
  }else{
   return false;
  }
  return arr;
}

mutation(['hello', 'hey']);

I'm seeking an explanation for why this solution doesn't work. Just understanding is required, not a direct answer. Thank you!

Appreciate your help

javascript arrays

Answer 1

Answer №1

Give this a shot:

$('#id').click(function() {
    var words = ['apple','orange'];
    var isMatching = false;
    for (i = 0; i < words[1].length; i++) {
        if(words[0].toLowerCase().indexOf(words[1][i].toLowerCase()) >= 0)
            isMatching = true;
        else {
            isMatching = false;
            break;
        }
    }
    if (isMatching)
        alert('true');  // If all characters of the second word are found in the first word
});

Answer 2

Give this a shot:

$('#id').click(function() {
    var words = ['apple','orange'];
    var isMatching = false;
    for (i = 0; i < words[1].length; i++) {
        if(words[0].toLowerCase().indexOf(words[1][i].toLowerCase()) >= 0)
            isMatching = true;
        else {
            isMatching = false;
            break;
        }
    }
    if (isMatching)
        alert('true');  // If all characters of the second word are found in the first word
});

Answer 3

Answer №2

It seems that you are lowercasing the first element and then attempting to find the second element within the first array. Your method will only work if the entire second element is found as a substring in the first element or if both elements are exactly the same.

Examples where your solution would work:

['hello', 'Hello']

['hello', 'ell']

['hello', 'He']

However, it will not work if the letters in the second string are rearranged compared to the first string. In such cases, your solution will fail with examples like:

['Alien', 'line']

['hello', 'elo']

['hello', 'Hol']

If the whole second word does not match the first word exactly, your solution will not be effective.

Please let me know if this explanation helps. I am happy to provide a solution if needed.

Answer 4

It seems that you are lowercasing the first element and then attempting to find the second element within the first array. Your method will only work if the entire second element is found as a substring in the first element or if both elements are exactly the same.

Examples where your solution would work:

['hello', 'Hello']

['hello', 'ell']

['hello', 'He']

However, it will not work if the letters in the second string are rearranged compared to the first string. In such cases, your solution will fail with examples like:

['Alien', 'line']

['hello', 'elo']

['hello', 'Hol']

If the whole second word does not match the first word exactly, your solution will not be effective.

Please let me know if this explanation helps. I am happy to provide a solution if needed.

Answer 5

Answer №3

Another answer explains that the code provided will not work because it tries to find the second string within the first string in its entirety, with the same order of letters. To fix this issue, you need to check each letter of the second string individually against the first string.

The approach we'll take is called "Programming in English and going backward". The main problem can be summarized in English as:

Does every letter match?

This can be represented in JavaScript as

letters_to_check . every(matches)

To determine letters_to_check, we can calculate it as input[1].toLowerCase().split('').

Next, we need to define the matches function, which translates to

Is the letter found in the string we're checking against?

Implementing this logic results in

function matches(letter) { return string_to_check_against.search(letter); }

Here, string_to_check_against refers to input[0].

The complete program looks like this:

function mutation(input) {

  // Check if a letter is in the string we're checking against.
  function matches(letter) { return string_to_check_against.search(letter); }

  var string_to_check_against = input[0].toLowerCase();
  var string_to_check         = input[1].toLowerCase();
  var letters_to_check        = string_to_check.split('');

  return letters_to_check . every(matches);

}

If you are working with ES6, the code can be written more concisely as

function mutation([source, target]) {
  return target   .
    toLowerCase() .
    split('')     .
    every(letter => source.toLowerCase().search(letter));
}

Answer 6

Another answer explains that the code provided will not work because it tries to find the second string within the first string in its entirety, with the same order of letters. To fix this issue, you need to check each letter of the second string individually against the first string.

The approach we'll take is called "Programming in English and going backward". The main problem can be summarized in English as:

Does every letter match?

This can be represented in JavaScript as

letters_to_check . every(matches)

To determine letters_to_check, we can calculate it as input[1].toLowerCase().split('').

Next, we need to define the matches function, which translates to

Is the letter found in the string we're checking against?

Implementing this logic results in

function matches(letter) { return string_to_check_against.search(letter); }

Here, string_to_check_against refers to input[0].

The complete program looks like this:

function mutation(input) {

  // Check if a letter is in the string we're checking against.
  function matches(letter) { return string_to_check_against.search(letter); }

  var string_to_check_against = input[0].toLowerCase();
  var string_to_check         = input[1].toLowerCase();
  var letters_to_check        = string_to_check.split('');

  return letters_to_check . every(matches);

}

If you are working with ES6, the code can be written more concisely as

function mutation([source, target]) {
  return target   .
    toLowerCase() .
    split('')     .
    every(letter => source.toLowerCase().search(letter));
}

Answer 7

Answer №4

Based on the output provided, it is necessary to compare each character in the second array with those in the first array. It is important to check for the presence of individual characters rather than comparing the entire strings directly as that would not yield accurate results.

Here is a suggested approach:

var arr =  ['Alien', 'line'];
var arr1 = ['hello','hey'];
var arr2 = ['hello','Hello'];
function mutation(arr) {
  var str1 = arr[0].toLowerCase();
  var str2 = arr[1].toLowerCase();
  var result = false;
  for (var i=0;i<str2.length;i++) {
    result = (str1.indexOf(str2[i]) !== -1);
    if (!result) break;
  }

  return result;
}

console.log('Result for first array : ', mutation(arr));
console.log('Result for second array :', mutation(arr1));
console.log('Result for third array :', mutation(arr2));

Answer 8

Based on the output provided, it is necessary to compare each character in the second array with those in the first array. It is important to check for the presence of individual characters rather than comparing the entire strings directly as that would not yield accurate results.

Here is a suggested approach:

var arr =  ['Alien', 'line'];
var arr1 = ['hello','hey'];
var arr2 = ['hello','Hello'];
function mutation(arr) {
  var str1 = arr[0].toLowerCase();
  var str2 = arr[1].toLowerCase();
  var result = false;
  for (var i=0;i<str2.length;i++) {
    result = (str1.indexOf(str2[i]) !== -1);
    if (!result) break;
  }

  return result;
}

console.log('Result for first array : ', mutation(arr));
console.log('Result for second array :', mutation(arr1));
console.log('Result for third array :', mutation(arr2));

Answer 9

Answer №5

This code showcases my implementation. The process involves converting both strings in the array to lowercase and then comparing them against each other.

The approach taken is to iterate through each letter of the shorter string, utilizing the indexOf function to verify its existence in the longer string. Each match increments either no1 or no2 accordingly.

If the values of no1 or no2 equal the length of the shorter string, it signifies that all letters in the shorter string are present in the longer string.

function mutation(arr) {

  // Convert both strings in the array to lowercase
  var val1 = arr[0].toLowerCase();
  var val2 = arr[1].toLowerCase();

  // Check if val2 is shorter than val1
  if(val1.length >= val2.length){
    var no1 = 0;
    // Iterate over every letter in val2 and check if it exists in val1
    for(var i = 0; i < val2.length; i++){
      if(val1.indexOf(val2[i]) != -1){
        // Increment by 1 upon a match
        no1++;
      }
    }
    // Verify if no1 equals the length of val2
    if(no1 == val2.length){
      return true;
    }else{
      return false;
    }
  }else if(val2.length > val1.length){
    var no2 = 0;
    for(var j = 0; j < val1.length; j++){
      if(val2.indexOf(val1[j]) != -1){
        no2++;
      }
    }

    if(no2 == val1.length){
      return true;
    }else{
      return false;
    }
  }        
}

Answer 10

This code showcases my implementation. The process involves converting both strings in the array to lowercase and then comparing them against each other.

The approach taken is to iterate through each letter of the shorter string, utilizing the indexOf function to verify its existence in the longer string. Each match increments either no1 or no2 accordingly.

If the values of no1 or no2 equal the length of the shorter string, it signifies that all letters in the shorter string are present in the longer string.

function mutation(arr) {

  // Convert both strings in the array to lowercase
  var val1 = arr[0].toLowerCase();
  var val2 = arr[1].toLowerCase();

  // Check if val2 is shorter than val1
  if(val1.length >= val2.length){
    var no1 = 0;
    // Iterate over every letter in val2 and check if it exists in val1
    for(var i = 0; i < val2.length; i++){
      if(val1.indexOf(val2[i]) != -1){
        // Increment by 1 upon a match
        no1++;
      }
    }
    // Verify if no1 equals the length of val2
    if(no1 == val2.length){
      return true;
    }else{
      return false;
    }
  }else if(val2.length > val1.length){
    var no2 = 0;
    for(var j = 0; j < val1.length; j++){
      if(val2.indexOf(val1[j]) != -1){
        no2++;
      }
    }

    if(no2 == val1.length){
      return true;
    }else{
      return false;
    }
  }        
}

Javascript Array Dilemmas

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Similar questions

Combine strings in PHP with an alert box in JavaScript

NextJS is throwing an error stating that the element type is invalid. It was expecting either a string for built-in components or a class/function for composite components, but instead received an object

User-initiated closure of popup triggers error during Google sign in

Remove chosen tags from the options list in Material UI Autocomplete Multiple

Load an image dynamically within a JavaScript function

Error: Attempting to access property 'propeller' of an undefined object has caused a TypeError

Validation is performed on the Bootstrap modal form, ensuring that the modal is only loaded after the

Personalizing MaterialUI's autocomplete functionality

Is it considered acceptable to modify classes in a stateless React component by adding or removing them?

`Why am I having difficulty transmitting HTML content with Node.js through Mailgun?`

Reload the Angular application and navigate to a different state

increase the selected date in an Angular datepicker by 10 days

Using Jade language in a standard web application without the need for Node.js

Body Parser causing unexpected output

The alert box fails to display in the correct orientation when the condition is activated

What could be the reason why my useRouter function isn't working as expected?

Steps to implement jQuery after executing the command "npm install jquery"

There seems to be a problem with the output when trying to display the message "You said ${reply}"

The Hidden Power of jQuery: Unleashing the Full Potential of .text()

What is the proper way to invoke render functions using Vue 3 composition API?