Strings

Two flavors of every transform:

c.transform(value)              // applied to each item (as a string)
c.transform(value, key)         // applied to each item's keyed value

All return a new collection. The keyed form shallow-clones each plain-object item via cloneForSet before applying the change, so the source items are not modified. (Class instances and nested object references are passed through; the clone is shallow.)

Append / prepend / concat

c.appendString(s, key?)         // item + s
c.prependString(s, key?)        // s + item
c.concatString(s, key?)         // identical to appendString for strings

collect(["Ada", "Bob"]).appendString("!");
//  ["Ada!", "Bob!"]

collect([{ name: "Ada" }]).appendString("!", "name");
//  [{ name: "Ada!" }]

Replace / remove

c.replaceString(search: string | RegExp, replacement: string, key?)
c.replaceAllString(search: string, replacement: string, key?)   // search is a string; promoted to `new RegExp(search, "g")`
c.removeString(search: string | RegExp, key?)                    // replace with ""
c.removeAllString(search: string, key?)                          // replace all with ""

collect(["aba", "aaa"]).replaceString("a", "x");
//  ["xba", "xaa"]

collect(["aba", "aaa"]).replaceAllString("a", "x");
//  ["xbx", "xxx"]

collect(["aaba"]).removeAllString("a");
//  ["b"]

replaceAllString ALWAYS does a global regex replace (the first arg is forced into new RegExp(s, "g")). If you pass a regex, that’s wrong — use replaceString(/regex/g, ...) instead.

Trim

c.trim(value?: string = " ", key?: string)

collect(["  hi  ", " x "]).trim();           // ["hi", "x"]
collect(["##a##", "#b#"]).trim("#");         // ["a", "b"]

Wraps reinforcements’ trim(string, chars), which strips repeated occurrences of chars from both ends.

Casting

c.string()         // each item via String(item)
c.number()         // each item via Number(item)
c.boolean()        // each item via Boolean(item)

collect([1, null, "x"]).string();       // ["1", "null", "x"]
collect(["1", "abc", ""]).number();     // [1, NaN, 0]
collect([0, 1, "", "x"]).boolean();     // [false, true, false, true]