The function fails to return any value, however console.log does output something

Question

The function fails to return any value, however console.log does output something

I am attempting to implement a JavaScript function that checks for repeated letters within a string. The goal is for the function to return false if any repeating letters are found, and true if no repeats are present. However, I am encountering an issue where the function does not provide a return value as expected. Essentially, I aim to compare two strings and output a boolean result based on their content.

function isIsogram(str) {
  let str1 = str.toLowerCase().split("");
  //console.log(str.toLowerCase())
  let str2 = []
  for (let i = 0; i < str1.length; i++) {
    //console.log(str1[i])
    if (str2.indexOf(str1[i]) === -1) {
      str2.push(str1[i])
    }
  }
  //console.log(str2)
  if (str2 === str1) {
    return true;
  } else return false;
}


console.log(isIsogram("abba"))

javascript

Answer 1

Answer №1

If you're looking to check for repeating characters in a string, you can use the following code snippet:

 function detectRepeatedChars(inputString){ 
     return inputString.split("").some(
            function(char,index,array){
                return array.lastIndexOf(char)!=index
            }
     );
 }

This solution is quite effective and easy to understand. Further details can be found here: Check for repeated characters in a string Javascript

Answer 2

If you're looking to check for repeating characters in a string, you can use the following code snippet:

 function detectRepeatedChars(inputString){ 
     return inputString.split("").some(
            function(char,index,array){
                return array.lastIndexOf(char)!=index
            }
     );
 }

This solution is quite effective and easy to understand. Further details can be found here: Check for repeated characters in a string Javascript

Answer 3

Answer №2

One way to enhance the efficiency of your code is by implementing the following algorithm:

function checkIsogram(str) {
  let foundCharacters = [];
  
  for (let index = 0; index < str.length; index++) {
      const character = str[index];
      if (foundCharacters.includes(character)) {
          return false;
      }
      foundCharacters.push(character);
  }
  
  return true;
}


console.log(checkIsogram("abc"));
console.log(checkIsogram("abccba"));

Answer 4

One way to enhance the efficiency of your code is by implementing the following algorithm:

function checkIsogram(str) {
  let foundCharacters = [];
  
  for (let index = 0; index < str.length; index++) {
      const character = str[index];
      if (foundCharacters.includes(character)) {
          return false;
      }
      foundCharacters.push(character);
  }
  
  return true;
}


console.log(checkIsogram("abc"));
console.log(checkIsogram("abccba"));

Answer 5

Answer №3

Comparing two arrays is not a simple task. A workaround is to join them into strings first before comparing.

function checkIsogram(str) {
  let string1 = str.toLowerCase().split("");
  
  let string2 = []
  for (let i = 0; i < string1.length; i++) {
    
    if (string2.indexOf(string1[i]) === -1) {
      string2.push(string1[i])
    }
  }

  if (string2.join('') === string1.join('')) {
    return true;
  } else return false;
}


console.log(checkIsogram("abba"))

Alternatively, there's a simpler solution using the Set data structure.

function checkIsogram(str) {
  return new Set(str.split('')).size === str.length
}

console.log(checkIsogram("abba"), checkIsogram("abc"))

Answer 6

Comparing two arrays is not a simple task. A workaround is to join them into strings first before comparing.

function checkIsogram(str) {
  let string1 = str.toLowerCase().split("");
  
  let string2 = []
  for (let i = 0; i < string1.length; i++) {
    
    if (string2.indexOf(string1[i]) === -1) {
      string2.push(string1[i])
    }
  }

  if (string2.join('') === string1.join('')) {
    return true;
  } else return false;
}


console.log(checkIsogram("abba"))

Alternatively, there's a simpler solution using the Set data structure.

function checkIsogram(str) {
  return new Set(str.split('')).size === str.length
}

console.log(checkIsogram("abba"), checkIsogram("abc"))

Answer 7

Answer №4

When comparing two arrays with characters in them, using str2 === str1 will not work as the strict equality operator, ===, is designed for primitive types such as strings or numbers, not arrays.

An easy solution in your code would be to convert both str1 and str2 to strings using the join method, and then compare them like this: str2.join('') === str1.join('').

To learn more about equality checks in JavaScript, visit this link. You can also find information about the join method here

P.S. - While this approach may not be the most optimal, it's a simple way to get started.

Answer 8

When comparing two arrays with characters in them, using str2 === str1 will not work as the strict equality operator, ===, is designed for primitive types such as strings or numbers, not arrays.

An easy solution in your code would be to convert both str1 and str2 to strings using the join method, and then compare them like this: str2.join('') === str1.join('').

To learn more about equality checks in JavaScript, visit this link. You can also find information about the join method here

P.S. - While this approach may not be the most optimal, it's a simple way to get started.

Answer 9

Answer №5

Here is my solution:

function checkIsogram(str) {
    let strArr = str.toLowerCase().split("");
    let uniqueChars = [];
    for (let j = 0; j < strArr.length; j++) {
        if (uniqueChars.indexOf(strArr[j]) === -1) {
            uniqueChars.push(strArr[j]);
        }
        else{
            return false;
        }
    }
    return true;
}


console.log(checkIsogram("hello")); // Should return false

Answer 10

Here is my solution:

function checkIsogram(str) {
    let strArr = str.toLowerCase().split("");
    let uniqueChars = [];
    for (let j = 0; j < strArr.length; j++) {
        if (uniqueChars.indexOf(strArr[j]) === -1) {
            uniqueChars.push(strArr[j]);
        }
        else{
            return false;
        }
    }
    return true;
}


console.log(checkIsogram("hello")); // Should return false

The function fails to return any value, however console.log does output something

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Similar questions

Establishing a standard flatiron-director route (within the element) using the polymer core-pages component

Timer repeatedly triggered until nausea ensued (native v8natives.js:1582)

Set up a custom JavaScript function to automatically refresh a webpage

jQuery Animation: Creative Menu Icon Display

What's the best way to modify HTML element classes using Javascript?

What is the best way to attach an attribute to a element created dynamically in Angular2+?

Textfield removal from the input range is requested

When using the setTimeout function to update the state, React useContext appears to be ineffective

A step-by-step guide on crafting a customized archetype for nodeJs projects

What is the syntax for creating a link tag with interpolation in Angular 2 / Ionic 2?

Steps to replace the content of an HTML file (such as modifying images) by clicking on an element in a separate HTML file

React Native Child Component State Update Issue

How can I effectively organize an Angular2 component library for optimal efficiency?

Replacing text within nested elements

Authenticate through navigation on an alternate component

What is the best way to handle an AJAX request within an if-else statement?

Troubleshooting a page refresh error displaying "file not found" when using [angular js + NodeJS/ExpressJS] - solving the

Can one look through a div to the one beneath it by moving the cursor?

Struggling to get your HTML to Express app Ajax post request up and running?

Having trouble uploading images from my personal computer onto Phaser 3