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====== JavaScript - Comments - Strip Comments ======

<code Javascript>
var CommentStripper = (function (window) {

    var SLASH = '/';
    var BACK_SLASH = '\\';
    var STAR = '*';
    var DOUBLE_QUOTE = '"';
    var SINGLE_QUOTE = "'";
    var NEW_LINE = '\n';
    var CARRIAGE_RETURN = '\r';

    var CommentStripper = function () {

    };

    CommentStripper.prototype = {

        string: '',
        length: 0,
        position: 0,
        output: null,

        getCurrentCharacter: function () {
            return this.string.charAt(this.position);
        },

        getPreviousCharacter: function () {
            return this.string.charAt(this.position - 1);
        },

        getNextCharacter: function () {
            return this.string.charAt(this.position + 1);
        },

        add: function () {
            this.output.push(this.getCurrentCharacter());
        },

        next: function () {
            this.position++;
        },

        atEnd: function () {
            return this.position >= this.length;
        },

        isEscaping: function () {
            if (this.getPreviousCharacter() == BACK_SLASH) {
                var offset = 1;
                var escaped = true;
                while ((this.position - offset) > 0) {
                    escaped = !escaped;
                    var current = this.position - offset;
                    if (this.string.charAt(current) != BACK_SLASH) {
                        return escaped;
                    }
                    offset++;
                }
                return escaped;
            }
            return false;
        },

        processSingleQuotedString: function () {
            if (this.getCurrentCharacter() == SINGLE_QUOTE) {
                this.add();
                this.next();
                while (!this.atEnd()) {
                    if (this.getCurrentCharacter() == SINGLE_QUOTE && !this.isEscaping()) {
                        return;
                    }
                    this.add();
                    this.next();
                }
            }
        },

        processDoubleQuotedString: function () {
            if (this.getCurrentCharacter() == DOUBLE_QUOTE) {
                this.add();
                this.next();
                while (!this.atEnd()) {
                    if (this.getCurrentCharacter() == DOUBLE_QUOTE && !this.isEscaping()) {
                        return;
                    }
                    this.add();
                    this.next();
                }
            }
        },

        processSingleLineComment: function () {
            if (this.getCurrentCharacter() == SLASH) {
                if (this.getNextCharacter() == SLASH) {
                    this.next();
                    while (!this.atEnd()) {
                        this.next();
                        if (this.getCurrentCharacter() == NEW_LINE || this.getCurrentCharacter() == CARRIAGE_RETURN) {
                            return;
                        }
                    }
                }
            }
        },

        processMultiLineComment: function () {
            if (this.getCurrentCharacter() == SLASH) {
                if (this.getNextCharacter() == STAR) {
                    this.next();
                    while (!this.atEnd()) {
                        this.next();
                        if (this.getCurrentCharacter() == STAR) {
                            if (this.getNextCharacter() == SLASH) {
                                this.next();
                                this.next();
                                return;
                            }
                        }
                    }
                }
            }
        },

        processRegex: function () {
            if (this.getCurrentCharacter() == SLASH) {
                if (this.getNextCharacter() != STAR && this.getNextCharacter() != SLASH) {
                    while (!this.atEnd()) {
                        this.add();
                        this.next();
                        if (this.getCurrentCharacter() == SLASH && !this.isEscaping()) {
                            return;
                        }
                    }
                }
            }
        },

        process: function () {
            while (!this.atEnd()) {
                this.processRegex();
                this.processDoubleQuotedString();
                this.processSingleQuotedString();
                this.processSingleLineComment();
                this.processMultiLineComment();
                if (!this.atEnd()) {
                    this.add();
                    this.next();
                }
            }
        },

        reset: function () {
            this.string = '';
            this.length = 0;
            this.position = 0;
            this.output = [];
        },

        strip: function (string) {
            this.reset();
            this.string = string;
            this.length = this.string.length;
            this.process();
            return this.output.join('');
        }

    };

    if (typeof define === 'function') {
        define('commentstripper', [], function () {
            return CommentStripper;
        });
    }

    return window.CommentStripper = CommentStripper;

})(window);
</code>

Usage is simple - create an instance and call .strip(string) to get back the de-commented string...

<code javascript>
var cs = new CommentStripper();
console.log( cs.strip(someString) );
</code>

It's intended to be 100% effective - catching any valid comment, including:

<code javascript>
var a = 10; // comment
var a = "http://www.github.com"; // more comments
var a = function(arg /*, ...rest */)
</code>

----

===== References =====

https://github.com/moagrius/stripcomments