Convert hyphens to camel case (camelCase)

Question

With regex (i assume) or some other method, how can i convert things like:

marker-image or my-example-setting to markerImage o

Answer 1

Here's my version of camelCase function:

var camelCase = (function () {
    var DEFAULT_REGEX = /[-_]+(.)?/g;

    function toUpper(match, group1) {
        return group1 ? group1.toUpperCase() : '';
    }
    return function (str, delimiters) {
        return str.replace(delimiters ? new RegExp('[' + delimiters + ']+(.)?', 'g') : DEFAULT_REGEX, toUpper);
    };
})();

It handles all of the following edge cases:

• takes care of both underscores and hyphens by default (configurable with second parameter)
• string with unicode characters
• string that ends with hyphens or underscore
• string that has consecutive hyphens or underscores

Here's a link to live tests: http://jsfiddle.net/avKzf/2/

Here are results from tests:

• input: "ab-cd-ef", result: "abCdEf"
• input: "ab-cd-ef-", result: "abCdEf"
• input: "ab-cd-ef--", result: "abCdEf"
• input: "ab-cd--ef--", result: "abCdEf"
• input: "--ab-cd--ef--", result: "AbCdEf"
• input: "--ab-cd-__-ef--", result: "AbCdEf"

Notice that strings that start with delimiters will result in a uppercase letter at the beginning. If that is not what you would expect, you can always use lcfirst. Here's my lcfirst if you need it:

function lcfirst(str) {
    return str && str.charAt(0).toLowerCase() + str.substring(1);
}