if map key contains code example

Example 1: check if a key is in a map

if ( m.find("f") == m.end() ) {
  // not found
} else {
  // found
}

Example 2: js check if map contains key

const map1 = new Map();
map1.set('bar', 'foo');

console.log(map1.has('bar'));
// expected output: true

console.log(map1.has('baz'));
// expected output: false