CODEWITHSUNDEEP
javascriptstringif-statementconditional-statements
Jacopo
Jacopo

Reputation: 163

Find the index of each letter of a given string, and return the same index if the letter is repeated

I'm trying to solve a fairly simple kata and find myself stuck to a conditional. I'm trying to return the same integer for a string that has the same letter more than once.

For example, for the string hello it should return 0.1.2.2.3.

This is my code so far:

const wordPattern = word => {
  word = word.toLowerCase();
  let index =[]
  
  for(i=0; i<word.length; i++){
    index.includes(i) ? word(i) === index[i] : index.push(i)
  }
    
  return index 
}

Thanks a lot in advance!

Upvotes: 0

Views: 69

Answers (2)

tarkh
tarkh

Reputation: 2549

You can look ahead in loop with regular if statement

const wordPattern = word => {
  word = word.toLowerCase();
  let index =[];
  // Because you don't want word letters index,
  // you can create separate index
  let c = 0;
  
  for(let i=0; i<word.length; i++){
    // Add c to index array
    index.push(c);
    // Increase c index
    c++;
    // Look ahead and do simple logic
    // by decreasing your c index if next
    // letter equals current
    if(word[i+1] && word[i+1] === word[i]) c--;
  }
    
  return index 
}

// Test
console.log(wordPattern('Hello').toString());
console.log(wordPattern('Success').toString());

Upvotes: 1

gbalduzzi
gbalduzzi

Reputation: 10176

I would use an object, because it provides me the ability to map a key (the letter) to a value (the integer assigned to that letter):

const wordPattern = word => {
  word = word.toLowerCase();
  const map = {}
  const output = []
  let counter = 0
  
  for(i=0; i<word.length; i++){
    if (!map[word[i]]) {
      map[word[i]] = counter
      counter++
    }
    output.push(map[word[i]])
  }
    
  return output 
}

You could also loop the string using for..of if you are using a modern enough javascript version (es6):

const wordPattern = word => {
  word = word.toLowerCase();
  const map = {}
  const output = []
  let counter = 0
  
  for(const l of word) {
    if (!map[l]) {
      map[l] = counter
      counter++
    }
    output.push(map[l])
  }
  return output 
}

Upvotes: 1

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