Online Lower Case Converter

I am trying to convert upper case letters to lower case and I get the following error:

 animalException in thread "main" java.lang.StringIndexOutOfBoundsException: String    index out of range: 6    at java.lang.String.charAt(Unknown Source)    at newproject.chars.main(chars.java:11)

Here is my code:

public class chars {    public static void main(String[] args) {           String a = "AnImAl";          for(int b=0;b<=a.length();b++) {          char c= a.charAt(b);          if(c>=65 && c<=90)          {             c=(char)((c + 32));          }          System.out.print(c);    }    }}

Could somebody explain to me why I get this error? Thanks in advance

I have to generate a random customer IDs in the format 'abc123DFG'. The first three letters have to be lowercase the next three are numbers and the next three uppercase letters. I could make it simple by using unicode but this would be too big of a code I think. I want to keep it short and efficient.

PS: I am actually a very bad programmer but somehow I made it through the first semester.

I am trying to convert a char element from an char *argv[] array to lowercase from uppercase without using a function. I want to add 32 to the ascii integer.

When I try to pass the variable as an argument, it will show the integer sum, but not the new lowercase character. Instead it shows the following output:

letter h, 104tolower: 136, �

Code:

int i = 0;for(i = 0; argv[1][i] != '\0'; i++) {    char letter = argv[1][i];    printf("letter %c, %i\n", letter, letter);    char tolower = argv[1][i];    int lowercase = tolower + 32;    printf("tolower: %i, %c\n", lowercase, lowercase);}

Why is it printing a "?" char?

Is there a way to convert a string from uppercase, or even part uppercase to lowercase?

E.g. Kilometers --> kilometers.

I am trying to create a function in which after toLowerCase() input, will then capitalize the first letter in each element of an array.

function title_case ( String ) {    var result = "";    var text = String.toLowerCase().split(" ");    for (var i = 0; i < text.length; i++) {      var c = text[i].charAt(0).toUpperCase();      result = result + c;    }    return result;  }

Input:

document.write( title_case( "a kitty PUrrs") );

The resulting output of the current code is AKP. I'm trying to figure out a way to delete lowercase character with charAt(1) and then join() for the output if possible. Am I on the right track? I know there are simpler methods, but I'm trying to learn something along these lines.