How to repeat a string in java?

  1. String. repeat() API [Since Java 11]
  2. Repeat string using regex [till Java 10]
  3. Apache Common’s StringUtils class.

How do you repeat a string?

The string can be repeated N number of times, and we can generate a new string that has repetitions. repeat() method is used to return String whose value is the concatenation of given String repeated count times. If the string is empty or the count is zero then the empty string is returned.

Can I multiply string in Java?

We can multiply string in java using appending a particular string in a loop using StringBuffer. append() and it will make sure that string is repeating n time. Another way is using String. … repeat() is also able to perform the same reputation of String.

Is there a repeat loop in Java?

The do/while loop is a variant of the while loop. This loop will execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true.

How do I find duplicate characters in a string?

  1. import java.util.HashMap;
  2. import java.util.Map;
  3. import java.util.Set;
  4. public class DuplicateCharFinder {
  5. public void findIt(String str) {
  6. Map baseMap = new HashMap();
  7. char[] charArray = str.toCharArray();

Can I multiply a string?

To (properly) multiply an string by an integer, you split the string into characters, repeat each character a number of times equal to the integer, and then stick the characters back together. If the integer is negative, we use its absolute value in the first step, and then reverse the string.

What is StringBuilder in Java?

StringBuilder objects are like String objects, except that they can be modified. Internally, these objects are treated like variable-length arrays that contain a sequence of characters. … For example, if you need to concatenate a large number of strings, appending to a StringBuilder object is more efficient.

What is str length in Java?

What is String “Length” Method in Java? … The string length method returns the number of characters written in the String. This method returns the length of any string which is equal to the number of 16-bit Unicode characters in the string.

What is loop example?

A loop is used for executing a block of statements repeatedly until a particular condition is satisfied. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration.

How do you repeat a while loop?

  1. The body of the loop is executed at first. Then condition is evaluated.
  2. If condition evaluates to true , the body of the loop inside the repeat statement is executed again.
  3. condition is evaluated once again.
  4. This process continues until condition evaluates to false . Then the loop stops.

Which statement is used to stop a loop?

The purpose the break statement is to break out of a loop early. For example if the following code asks a use input a integer number x. If x is divisible by 5, the break statement is executed and this causes the exit from the loop.

Why is * called string repetition operator?

We are accustomed to using the * symbol to represent multiplication, but when the operand on the left side of the * is a tuple, it becomes the repetition operator. The repetition operator makes multiple copies of a tuple and joins them all together. Tuples can be created using the repetition operator, *.

What is the function of while loop?

The while loop is used to repeat a section of code an unknown number of times until a specific condition is met. For example, say we want to know how many times a given number can be divided by 2 before it is less than or equal to 1.

How do you repeat a string in C++?

There’s no direct idiomatic way to repeat strings in C++ equivalent to the * operator in Python or the x operator in Perl. If you’re repeating a single character, the two-argument constructor (as suggested by previous answers) works well: std::string(5, ‘. ‘)

How do you find duplicates in a string in Java?

  1. Split the string into character array.
  2. Iterate over character array.
  3. For each iteration, use character as map key and check is same character is present in map, already.
  4. If map key does not exist it means the character has been encountered first time.

How do I find duplicates in a string python?

  1. First split given string separated by space.
  2. Now convert list of words into dictionary using collections. Counter(iterator) method. Dictionary contains words as key and it’s frequency as value.
  3. Now traverse list of words again and check which first word has frequency greater than 1.