count-the-smiley-faces.js

// -Each smiley face must contain a valid pair of eyes. Eyes can be marked as : or ;
// -A smiley face can have a nose but it does not have to. Valid characters for a nose are - or ~
// -Every smiling face must have a smiling mouth that should be marked with either ) or D.
// No additional characters are allowed except for those mentioned.
// Valid smiley face examples:
// :) :D ;-D :~)
// Invalid smiley faces:
// ;( :> :} :] 


//return the total number of smiling faces in the array
function countSmileys(arr) {
  // a place to keep track of the current count
  let count = 0;

  // iterate over the array
  for (let i = 0; i < arr.length; i++) {
    // iterate over the current face if the length of the face is either 2 or 3
    const face = arr[i];
    if (face.length == 2 || face.length == 3) {
      // if the first character is a : ;
      if (face[0] == ':' || face[0] == ';') {
        // if the second character is a - ~
        if (face[1] == '-' || face[1] == '~') {
          // if the third character is a ) D
          if (face[2] == ')' || face[2]  == 'D') {
            // increment count
            count++;
          }
        } else if ((face[1] == ')' || face[1]  == 'D') && face.length == 2) {
          // else if the second character is a ) D && the length is 2
          // increment count
          count++;
        }
      }
    }
  }

  // return count
  return count;
}

function countSmileys(arr) {
  let count = 0;

  const eyes = {
    ':': true,
    ';': true
  };

  const noses = {
    '-': true,
    '~': true
  };

  const mouths = {
    ')': true,
    'D': true
  };

  for (let i = 0; i < arr.length; i++) {
    const face = arr[i];
    if (face.length == 2) {
      if (eyes[face[0]] && mouths[face[1]]) {
        count++;
      }
    } else if (face.length == 3) {
      if (eyes[face[0]] && noses[face[1]] && mouths[face[2]]) {
        count++;
      }
    }
  }

  return count;
}

function countSmileys(arr) {
  const eyes = {
    ':': true,
    ';': true
  };

  const noses = {
    '-': true,
    '~': true
  };

  const mouths = {
    ')': true,
    'D': true
  };

  return arr.reduce((count, face) => {
    if (face.length == 2) {
      if (eyes[face[0]] && mouths[face[1]]) {
        count++;
      }
    } else if (face.length == 3) {
      if (eyes[face[0]] && noses[face[1]] && mouths[face[2]]) {
        count++;
      }
    }
    return count;
  }, 0);
}