Use array.reduce to join strings with comma, but avoid the extra comma

Question

I have an array of objects to be transformed and merged into a single string with array.reduce.

const arr = [{id: 7, task: "foo"}, {id: 22, task: "bar"}]

The result should be 7. foo, 22. bar

If I write this code, it will work but produce , 7. foo, 22.bar:

arr.reduce((pre,cur)=> pre + `, ${cur.id}. ${cur.task}`, '')

How can I properly do this without the extra comma, preferably only in FP?

Answer 1

Is reduce a requirement? Map is easier to understand and read.

arr.map(o => `${o.id}. ${o.task}`).join(',')