How to repeat part of a switch statement without duplicating code / alternatives-CodePudding

I am creating a random sentence generator. The sentence generated will hold values that have been randomly selected from an objects properties. properties are; nouns, tenses, adjectives conjunctions.

The sentence will be in the order of "noun tense adjective conjunction noun tense adjective" Example output = "Birds will be wild and robots will be free"

I have created this using for in loop switch statements, however I have repeated code in order to do so. I'm wondering is there is a more efficient way to do this?

Code:

// Generating a random number
function generateRandomNumber(num) {
  return Math.floor(Math.random() * num)
}

// The object containing the properties and values, the values will be the words in the sentence.
const sentenceElements = {
  nouns: [ 'animals', 'elephants', 'mice', 'monkeys', 'lions', 'zebras', 'people', 'buildings', 'trees', 'flowers', 'bugs', 'cats', 'birds', 'mushrooms', 'computers', 'robots', 'dinosaurs' ],
  tenses: [ 'were', 'are', 'will be',  ],
  adjectives: [ 'best', 'bad', 'better', 'huge', 'busy', 'free', 'great', 'hard', 'loud', 'old', 'right', 'special', 'weird', 'brave', 'wild', 'adorable', 'smart', 'crazy', 'cute', 'funny' ],
  conjunctions: [ 'because', 'however', 'since', 'but', 'whereas', 'and', 'also', 'as', 'when' ]
}

// Empty array for the selected words to be pushed into
let newArray = []

// Looping through the properties in the object to push each randomly selected value into the empty array.
for(let i in sentenceElements) {
  let randArrayIndex = generateRandomNumber(sentenceElements[i].length)

  switch(i) {
    case 'nouns':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
    case 'tenses':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
    case 'adjectives':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
    case 'conjunctions':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
  }
}
// Used another for in loop to add more words to the array using the same object.
for(let i in sentenceElements) {
  let randArrayIndex = generateRandomNumber(sentenceElements[i].length)

  switch(i) {
    case 'nouns':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
    case 'tenses':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
    case 'adjectives':
      newArray.push(`${sentenceElements[i][randArrayIndex]}`)
      break
  }
} 
// Adding the values from newArray to a string called completeSentence while capitalizing the first letter
function completeSentence(sentence) {
  const formatting = newArray.join(' ') 
  const formatted = formatting[0].toUpperCase()   formatting.substring(1)
  console.log(formatted)
}

completeSentence(newArray);

Thanks

CodePudding user response：

Your code is tightly coupling the order of the sentenceElements object's keys to the structure of the sentence. This makes it needlessly inflexible.

Instead, you can create a function that generates a random sentence element of a given type:

function randomSentenceElement(type) {
    const elements = sentenceElements[type]
    return elements[generateRandomNumber(elements.length)]
}

Then you can easily compose sentences in any order you wish, with much less code:

let newArray = ['nouns', 'tenses', 'adjectives', 'conjunctions', 'nouns', 'tenses', 'adjectives']
    .map(randomSentenceElement)

CodePudding user response：

In a simple form, if you just want to remove the duplicated switch you could add a while loop, around your switch and another int variable, which will loop for 'x' number of sentences you want to generate. The below should loop 2 times for you.

let newArray = []
let sentencesToGenerate = 2;

while (newArray.length < sentencesToGenerate)
{
    // Looping through the properties in the object to push each randomly selected value into the empty array.
    for(let i in sentenceElements) {
      let randArrayIndex = generateRandomNumber(sentenceElements[i].length)

      switch(i) {
        case 'nouns':
          newArray.push(`${sentenceElements[i][randArrayIndex]}`)
          break
        case 'tenses':
          newArray.push(`${sentenceElements[i][randArrayIndex]}`)
          break
        case 'adjectives':
          newArray.push(`${sentenceElements[i][randArrayIndex]}`)
          break
        case 'conjunctions':
          newArray.push(`${sentenceElements[i][randArrayIndex]}`)
          break
      }
    }
    sentencesToGenerate  ;
}