const f = ifn([
  ['foo', 'value is string'],
  [0, 'value is number'],
  [{}, 'value is object']
  ['func', () => 'value is function']
], 'default value'); // default value is optional

console.log(f('foo'))   // value is string
console.log(f(0))       // value is number
console.log(f({}))      // value is object
console.log(f('func'))  // value is function
console.log(f([]))      // default value