1323. Maximum 69 Number.js

// You are given a positive integer num consisting only of digits 6 and 9.

// Return the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).

// Example 1:

// Input: num = 9669
// Output: 9969
// Explanation:
// Changing the first digit results in 6669.
// Changing the second digit results in 9969.
// Changing the third digit results in 9699.
// Changing the fourth digit results in 9666.
// The maximum number is 9969.
// Example 2:

// Input: num = 9996
// Output: 9999
// Explanation: Changing the last digit 6 to 9 results in the maximum number.
// Example 3:

// Input: num = 9999
// Output: 9999
// Explanation: It is better not to apply any change.

const maximum69Number = num => Number(num.toString().replace('6', '9'))

// const maximum69Number = num => {
// 	const clone = String(num).split('')
// 	const index = clone.indexOf('6')
// 	if (index !== -1) {
// 		clone[index] = 9
// 	}
// 	return clone.join('')
// }