C program to find repeated characters in a string

An example of the code using double loop return true or false based on if there are repeated characters in a string :. You could use javascript builtin Array functions some MDN some reference.

Details to the some function can be found here. Meaning, if the first occurrence of the character is also the last occurrence, then you know it doesn't repeat. If not true, then it does repeat. So it would be better to use an object to map and remember the characters to check for uniqueness or duplicates. Assuming a maximum data size for each character, this process will be an O n algorithm.

Note that JavaScript strings are defined as sequences of bit unsigned integer values. Hence, we can still implement the same basic algorithm but using a much quicker array lookup rather than an object lookup. The result is approximately times faster now. The Set object lets you store unique values of any type, whether primitive values or object references. It has some methods to add or to check if a property exist in the object.

Read more about Sets at MDN. How are we doing? Please help us improve Stack Overflow. Take our short survey. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Check for repeated characters in a string Javascript Ask Question. Asked 6 years, 2 months ago.

Active 17 days ago. Viewed 75k times. As well as demo example. View all posts by Admin. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Take input string from user, store it in some variable. Find and remove all repeated characters of the given string. Angular 7. Machine Learning. Data Structures. Operating System. Computer Network. Compiler Design. Computer Organization. Discrete Mathematics. Ethical Hacking. Computer Graphics.

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