Convert string to camel case in Java

In this Blog, we will learn how the camel case works in Java with a clear and understandable example. In Java, camel case is nothing but a Naming Convention . I know you are thinking about what is naming convention is, it is  a set of  rules used to name variables, methods, etc.

Some rules to follow

• The starting word starts with lowercase letter.
• The next word starts with an uppercase letter.
• It doesn’t  allow spaces, dashes (-), or underscores ( _ )

Example

welcome to-code_speedy  ->  welcomeToCodeSpeedy

Here in this example, I changed the first word’s starting letter to lowercase, then I  changed every first letter to uppercase after a special character.

Code

String[] splitIntoWords = input.split("[\\s-_]+");

Here we are using the inbuilt split method in Java to split the String into words separated by special characters.

\\s: this is for whitespaces.

-: This is for hyphen.

_:  This is for underscore.

 +: This means it matches one or more of the characters.

StringBuilder result = new StringBuilder(words[0].toLowerCase());

Here, the meaning of this code snippet is converting the first word’s first letter to lowercase using the StringBuilder class in Java.

for(int i = 1; i<splitIntoWords.length;i++) {
    String word= splitIntoWords[i];
    if (word.length()>0) {
        camelCase.append(Character.toUpperCase(word.charAt(0)));
        camelCase.append(word.substring(1).toLowerCase());
    }
}

In this code, there are some operations performed. I’ll explain it line by line.

• The first line is a loop for converting the words into camel case.
• The second line is taking each word from the array.
• The third line is a conditional statement it checks whether the word length is greater than zero or not.
• Then the next line is performing operations the toUpperCase() method used to convert a single character into uppercase. for camel case, we need to convert every starting letter of the word except the first word.
• The final line converts the remaining letters into lowercase using a method toLowerCase() method. method
• The final step is to append to the string.

Advantages:

• Easy to read.
• Easy to Understand.
• Easy to maintain.
• More consistent for team projects.