CODEWITHSUNDEEP
javascriptarraysloops
Metawaa
Metawaa

Reputation: 366

JavaScript foreach an array and split them with commas and last one's comma with "and"

I need to know how I can split an array with commas and if it's the last one element to the last one I have , and and if it's the last one I add . to it. I have the following code. The output as one big string honda, audi, tesla, and toyota. the following is printing more than one. Also what if I wanted to push it one time into new array. So one big array of string ["honda, audi, tesla, and toyota."]

let namesArray = ["honda", "audi", "tesla", "toyota"];
let newOrder = ""
namesArray.forEach((item, index) => {
  console.log(index);

  if (index === namesArray.length - 2) {
    newOrder = item + ' , and'
  } else if (index === namesArray.length - 1) {
    newOrder = (item + '.')
  } else {
    newOrder = (item + ',')
  }

})
console.log('new string ', newOrder)

"new string ", "honda,audi,tesla,toyota."

Upvotes: 0

Views: 2066

Answers (3)

StackSlave
StackSlave

Reputation: 10617

I would create a function for reuse. First make a .slice() of your array, so the original is not affected. .pop() off the last Array element. Then .join(', ') and concatenate +', and ' along with the element you popped off +'.'.

function andIt(array){
  const a = array.slice(), p = a.pop()+'.';
  if(!a.length){
    return p;
  }
  return a.join(', ')+', and '+p;
}
const namesArray = ['honda', 'audi', 'tesla', 'toyota'];
console.log(andIt(namesArray)); console.log(andIt(['test']));

Upvotes: 0

DecPK
DecPK

Reputation: 25401

You can easily achieve this result using map and join

const arr = ["honda", "audi", "tesla", "toyota"];

const result = arr
  .map((item, index) => {
    if (index === arr.length - 1) {
      return `and ${item}.`;
    } else {
      return `${item}, `;
    }
  })
  .join("");
console.log(result);

You can also use string template literal if the array size in known prior

const arr = ["honda", "audi", "tesla", "toyota"];
const [a, b, c, d] = arr;
const result = `${a}, ${b}, ${c}, and ${d}.`;
console.log(result);

Upvotes: 2

Nick
Nick

Reputation: 147276

In terms of what is wrong with your existing code, you are not adding the new string value to your output (i.e. use newOrder +=, not newOrder = in the loop):

let namesArray = ["honda", "audi", "tesla", "toyota"];
let newOrder = ""
namesArray.forEach((item, index) => {
  if (index === namesArray.length - 2) {
    newOrder += item + ', and '
  } else if (index === namesArray.length - 1) {
    newOrder += (item + '.')
  } else {
    newOrder += (item + ', ')
  }

})
console.log(newOrder)

It would be simpler though to just join a slice of the array from the start to the second to last element, then add , and and the last element to that string:

let namesArray=["honda", "audi", "tesla", "toyota"];

let newOrder = namesArray.slice(0,-1).join(', ') + ', and ' + namesArray.slice(-1) + '.';

console.log(newOrder)

Upvotes: 4

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