head - nodef/extra-set GitHub Wiki

Get first value from set (default order).

Similar: head, tail.

function head(x, vd?)
// x:  a set
// vd: default value

const set = require('extra-set');

var x = new Set([1, 2, 3]);
set.head(x);
// → 1

var x = new Set();
set.head(x, -1);
// → -1

References

• Data.List.head: Haskell
• _.head: lodash
• Array.first: sugarjs