---
id: 596e414344c3b2872167f0fe
title: Comma quibbling
challengeType: 5
forumTopicId: 302234
dashedName: comma-quibbling
---
# --description--
Comma quibbling is a task originally set by Eric Lippert in his blog.
# --instructions--
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
- An input of no words produces the output string of just the two brace characters (
"{}"
)
- An input of just one word, e.g.
["ABC"]
, produces the output string of the word inside the two braces, e.g. "{ABC}"
- An input of two words, e.g.
["ABC", "DEF"]
, produces the output string of the two words inside the two braces with the words separated by the string " and "
, e.g. "{ABC and DEF}"
- An input of three or more words, e.g.
["ABC", "DEF", "G", "H"]
, produces the output string of all but the last word separated by ", "
with the last word separated by " and "
and all within braces; e.g. "{ABC, DEF, G and H}"
Test your function with the following series of inputs showing your output here on this page:
- [] # (No input words).
- ["ABC"]
- ["ABC", "DEF"]
- ["ABC", "DEF", "G", "H"]
**Note:** Assume words are non-empty strings of uppercase characters for this task.
# --hints--
`quibble` should be a function.
```js
assert(typeof quibble === 'function');
```
`quibble(["ABC"])` should return a string.
```js
assert(typeof quibble(['ABC']) === 'string');
```
`quibble([])` should return "{}".
```js
assert.equal(quibble(testCases[0]), results[0]);
```
`quibble(["ABC"])` should return `"{ABC}"`.
```js
assert.equal(quibble(testCases[1]), results[1]);
```
`quibble(["ABC", "DEF"])` should return `"{ABC and DEF}"`.
```js
assert.equal(quibble(testCases[2]), results[2]);
```
`quibble(["ABC", "DEF", "G", "H"])` should return `"{ABC, DEF, G and H}"`.
```js
assert.equal(quibble(testCases[3]), results[3]);
```
# --seed--
## --after-user-code--
```js
const testCases = [[], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]];
const results = ["{}", "{ABC}", "{ABC and DEF}", "{ABC, DEF, G and H}"];
```
## --seed-contents--
```js
function quibble(words) {
return true;
}
```
# --solutions--
```js
function quibble(words) {
return "{" +
words.slice(0, words.length - 1).join(", ") +
(words.length > 1 ? " and " : "") +
(words[words.length - 1] || '') +
"}";
}
```