regexp-flags.js

// Add flag 'g' if it isn’t there, yet

// Solution 1
let cloneFlags = regExp.flags;
if (!cloneFlags.includes('g')) {
  cloneFlags += 'g';
}

// Solution 2
const cloneFlags = regExp.flags.includes('g')
  ? regExp.flags
  : regExp.flags + 'g';

// Solution 3
const f = regExp.flags;
const cloneFlags = f.includes('g') ? f : f+'g';

// Solution 4
const cloneFlags = [...new Set(regExp.flags + 'g')].join('');