CODEWITHSUNDEEP
javascript
felishaww
felishaww

Reputation: 39

How to check if an item in an array is a letter?

so there's this exercise on coderbyte that goes:

Have the function SimpleSymbols(str) take the str parameter being passed and determine if it is an acceptable sequence by either returning the string true or false. The str parameter will be composed of + and = symbols with several characters between them (ie. ++d+===+c++==a) and for the string to be true each letter must be surrounded by a + symbol. So the string to the left would be false. The string will not be empty and will have at least one letter.

sample test cases:

Input:"+d+=3=+s+"

Output:true

Input:"f++d+"

Output:false

and here is the solution that i came up with, but it's not working:

function SimpleSymbols(str) { 

  // code goes here 

  var splitted = str.split('')
  var result = splitted.map(function (arr){
      for (var i=0; i<splitted.length; i++){
          if (splitted[i] == '+' && splitted[i+2] == '+' && splitted[i+1] == /[a-z]/gi || && splitted[i+1] == /[A-Z]/gi){
              return true
          }
          return false
      }
      }
  })

 return result;

}

// keep this function call here 
SimpleSymbols(readline());

i believe the problem lies within how I wrote the regex condition on the if statement.

so how is the right way to found out that splitted[i+1] is a letter?

Upvotes: 1

Views: 3126

Answers (5)

mrJoe
mrJoe

Reputation: 500

I believe this is the simplest solution. Just walk the string and check if each found letter is surrounded by + on both sides.

function isEachLetterSurroundedByPlus(str) {
    const re = /[a-z]/i;
    for (let i = 0; i < str.length; i++) {
        if (re.test(str[i])) {
            if (str[i - 1] !== "+" || str[i + 1] !== "+")
                return false;
        }
    }
    return true;
}

console.log(isEachLetterSurroundedByPlus("+s+f+=+d+d=d+"));
console.log(isEachLetterSurroundedByPlus("+s+f+=+d+d+=+d+"))

Upvotes: 0

DanieleAlessandra
DanieleAlessandra

Reputation: 1555

You may search for a charecter surrounded by something different than the plus symbol and return false when you find it. Something like this:

function isValid(str) {
  return !str.match(/\+[a-z]([^+]|$)|([^+]|^)[a-z]([^+]|$)|([^+]|^)[a-z]\+/gi);
}

isValid("+d+=3=+s+"); /// --> true
isValid("f++d+"); /// --> false

Upvotes: 0

Code Maniac
Code Maniac

Reputation: 37755

You're for loop on splittedArray inside map doesn't make sense, you can directly use index parameter of map

`.map(currentValue, index, array)`

And also you're not using regex to test string, you're comparing string with regex,

`splitted[i+1] == /[a-z]/gi`

if you want to use regex you can use this pattern

(?:^|[^+])[a-z]|[a-z](?:[^+]|$)

enter image description here

let inputs = ["+d+=3=+s+","f++d+"]

let check = (str) => +(str.match(/(?:^|[^+])[a-z]|[a-z](?:[^+]|$)/gi) || []).length > 0

inputs.forEach(str=> console.log(check(str)))

Upvotes: 1

SHUBHAM SINGH
SHUBHAM SINGH

Reputation: 377

function SimpleSymbols(str) { 

  // code goes here

  var splitted = str.split('')
  var result = splitted.map(function (arr){
      for (var i=0; i<splitted.length; i++){
          if (splitted[i] == '+' && splitted[i+2] == '+' && 
          (/^[a-zA-Z]+$/.test(splitted[i+1])))
          {
console.log('true');              
return true;
          }else{
          console.log('false');
          return false;
      }
      }
  })

 return result;

}

SimpleSymbols('+d+=3=+s+');

Upvotes: 1

Sabee
Sabee

Reputation: 1811

Something like this

function SimpleSymbols(str) { 

  // code goes here 

  var splitted = str.split('+')
  var result = splitted.map(function (arr){
      for (var i=0; i < splitted.length; i++){
           if ( /[a-z]/gi.test(splitted[i]) &&  /[A-Z]/gi.test(splitted[i+1])
           ){
              return true
          }
          return false
      
      }
  })

 return result;

}

// keep this function call here 
console.log(SimpleSymbols('f+g+j'));

Upvotes: 1

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