Convert camelCaseText to Sentence Case Text

const text = 'helloThereMister';
const result = text.replace(/([A-Z])/g, " $1");
const finalResult = result.charAt(0).toUpperCase() + result.slice(1);
console.log(finalResult);

capitalize the first letter - as an example. Note the space in " $1".

Of course, in case the first letter is already capital - you would have a spare space to remove.

Alternatively using lodash:

lodash.startCase(str);

Example:

_.startCase('helloThere');
// ➜ 'Hello There'

Lodash is a fine library to give shortcut to many everyday js tasks.There are many other similar string manipulation functions such as camelCase, kebabCase etc.

I had a similar problem and dealt with it like this:

stringValue.replace(/([A-Z]+)*([A-Z][a-z])/g, "$1 $2")

For a more robust solution:

stringValue.replace(/([A-Z]+)/g, " $1").replace(/([A-Z][a-z])/g, " $1")

http://jsfiddle.net/PeYYQ/

Input:

 helloThere 
 HelloThere 
 ILoveTheUSA
 iLoveTheUSA

Output:

 hello There 
 Hello There 
 I Love The USA
 i Love The USA

Example without side effects.

function camel2title(camelCase) {
  // no side-effects
  return camelCase
    // inject space before the upper case letters
    .replace(/([A-Z])/g, function(match) {
       return " " + match;
    })
    // replace first char with upper case
    .replace(/^./, function(match) {
      return match.toUpperCase();
    });
}

In ES6

const camel2title = (camelCase) => camelCase
  .replace(/([A-Z])/g, (match) => ` ${match}`)
  .replace(/^./, (match) => match.toUpperCase())
  .trim();