Given a string and the task is to format the string into the License key.
Rules:
- The input string contains alphanumeric characters and dashes
- The input string is separated by N+1 groups using N dashes.
- The output string must be grouped by K characters using a dash.
- The first group can be less than K characters but not Zero.
- The output string must not contain any lowercase character.
You have given the input string str and number K
Example:
Input: str = "dsf354g4dsg1" k = 4 Output: "DSF3-54G4-DSG1" Input: str = "d-sf354g4ds-g1dsfgdf-sfd5ds65-46" k = 6 Output: "D-SF354G-40DSGS-FGFSFD-DS6546" Input: str = " d-sf354';.;.';.'...,k/]gcs-hsfgdf-sfs6-46" Output: k = 5 Output: "DS-F354K-GCSHS-FGDFS-FS646"
To solve this problem we use the following steps:
- Create a function that takes two arguments str and k.
- Remove leading and ending white spaces using String.trim() method.
- Replace all the special characters using the String.replace() method and by searching with regex /[^a-zA-Z0-9]/g.
- Transform the string characters into uppercase by using String.toUpperCase() method.
- Convert the string into Array using the String.split() method. Now you have str is an array in which all the elements are uppercase characters and numbers (in the string form).
- Use a for loop and initialize the loop with the length of str and run it until the i is greater than 0 and after every iteration, the value of i decreases by k. Basically, we want a loop that runs from the backside of the str.
- Now concatenate the string at every iteration with a dash “-“
- Now on the str using Array.join() method convert the str into String and return the string from the function.
Javascript
<script> function format(str, k) { str = str // Remove the white spaces .trim() // Replace all the special // characters with "" .replace(/[^a-zA-Z0-9]/g, "" ) // Transform the string into // uppercase characters .toUpperCase() // Convert the string into array .split( "" ); // Store the length of the // array into len let len = str.length; for (let i = len; i > 0; i = i - k) { if (i != len) { // Concatenate the string with "-" str[i - 1] = str[i - 1] + "-" ; } } // Join the array to make it a string return str.join( "" ); } console.log(format( "dsf354g4dsg1" , 4)) console.log(format( "d-sf354g40ds-gsfgf-sfdds65-46" , 6)) console.log(format( " d-sf354';.;.';.'...,k/]gcs-hsfgdf-sfs6-46" , 5)) </script> |
Output:
"DSF3-54G4-DSG1" "D-SF354G-40DSGS-FGFSFD-DS6546" "DS-F354K-GCSHS-FGDFS-FS646"