https://github.com/aakashcode12/importantjava-functions

The important java functions which can be used in future
https://github.com/aakashcode12/importantjava-functions

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The important java functions which can be used in future

• Host: GitHub
• URL: https://github.com/aakashcode12/importantjava-functions
• Owner: AakashCode12
• Created: 2020-09-18T21:55:51.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2020-10-01T19:59:32.000Z (almost 5 years ago)
• Last Synced: 2025-02-07T19:33:37.273Z (5 months ago)
• Size: 8.79 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Important Java Functions

### Function to check a palindrome string

    public static boolean palindromeString(String s) {

      StringBuilder sb = new StringBuilder();

      sb.append(s);

      sb.reverse();

      String reversedString = sb.toString();

      if (reversedString.equals(s)) {

          return true;

      } else {

          return false;

      }

    }

### Inserting a character in a String

      public static String insertCharacterInBetween(String str, char cr, int index) {

            /*  !here the str is original String,

                !cr is the character to be inserted and

                !index is the index at which we need to insert the character

            */

            str = str.substring(0, index) + cr + str.substring(index + 1);// modified string

            return str;

        }

### Sort a String function in java

    public static String sortAlphabeticallyString(String str) {

            char charArray[] = str.toCharArray();

            Arrays.sort(charArray);

            return new String(charArray);

        }

### to Sort a string or alphabet if we have its position in array

##### If we have something like arr[]={0,3,1} & str[]={"a","d","b"} as input. & we want to sort the alphabetical order stored in string.

##### Then we can sort it using this code. We can't use the Arrays.sort(charArray); in some cases when we also need the indexes in the array.

##### here we have arr[] with all the indexes and str[] with all the strings..

     int temp = 0;

     String tempstr = "";

     for (int i = 0; i < n - 1; i++) {

                for (int j = i + 1; j < n; j++) {

                    if (arr[j] < arr[i]) {

                        temp = arr[i];

                        arr[i] = arr[j];

                        arr[j] = temp;

                    tempstr = str[i];

                    str[i] = str[j];

                    str[j] = tempstr;

                }

            }

        }