View difference between Paste ID: 8eTUB5AS and 1CmTv9LZ

 function activationKey(arr = []) {
     let key = arr[0];
 
     for (let i = 1; i < arr.length; i++) {
         const tokens = arr[i].split('>>>');
         const command = tokens[0];
 
         if (command === 'Generate') {
             break;
 
         } else if (command === 'Contains') {
             const substring = tokens[1];
 
             if (key.includes(substring)) {
                 console.log(`${key} contains ${substring}`);
             } else {
                 console.log('Substring not found!');
             }
         } else if (command === 'Flip'){
             const typeOfCommand = tokens[1];
             const startIndex = Number(tokens[2]);
             const endIndex = Number(tokens[3]);
             let changedKey = key.substring(startIndex, endIndex);
 
             if (typeOfCommand === 'Lower') {
                 changedKey = changedKey.toLowerCase();
                 key = key.substring(0, startIndex) + changedKey + key.substring(endIndex);
             } else if (typeOfCommand === 'Upper') {
                 changedKey = changedKey.toUpperCase();
                 key = key.substring(0, startIndex) + changedKey + key.substring(endIndex);
             }
             console.log(key);
         } else if (command === 'Slice') {
             const startIndex = Number(tokens[1]);
             const endIndex = Number(tokens[2]);
 
             key = key.substring(0, startIndex) + key.substring(endIndex);
 
             console.log(key);
         }
     }
 
     console.log(`Your activation key is: ${key}`);
 }