Joins all elements of an array into a string and returns this string.
Uses a separator and an end separator.
Use Array.prototype.reduce()
to combine elements into a string.
Omit the second argument, separator
, to use a default separator of ','
.
Omit the third argument, end
, to use the same value as separator
by default.
代码片段
const join = (arr, separator = ',', end = separator) =>
arr.reduce(
(acc, val, i) =>
i === arr.length - 2
? acc + val + end
: i === arr.length - 1
? acc + val
: acc + val + separator,
''
);
使用样例
join(['pen', 'pineapple', 'apple', 'pen'], ',', '&'); // "pen,pineapple,apple&pen"
join(['pen', 'pineapple', 'apple', 'pen'], ','); // "pen,pineapple,apple,pen"
join(['pen', 'pineapple', 'apple', 'pen']); // "pen,pineapple,apple,pen"