search - nodef/extra-map GitHub Wiki

Find key of an entry passing a test.

Alternatives: search, searchAll. Similar: find, search, searchValue.

function search(x, ft)
// x:  a map
// ft: test function (v, k, x)

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

var x = new Map(['a', 1], ['b', 2], ['c', 3], ['d', 2](/nodef/extra-map/wiki/'a',-1],-['b',-2],-['c',-3],-['d',-2));
map.search(x, v => v === 2);
// → 'b'                     ^

map.search(x, v => v === 4);
// → undefined

References