class declaration - Property does not exist on type in TypeScript

Question

I'm new to typescript, and trying to for a javascript code I've into typescript, so I ended up with the below code. My understanding regarding the classes in typescript is the below, which may be wrong, is: 1. After defining the class, you have to declare the parameters to be used later on with this, the deceleration is in the form of variableName:variableType. 2. in the constructor, the variables can assign values as this.variableName = x 3. In the methods under the class the variable can be used with this.

In the below code, I got the error [ts] Property 'escapeRegExp' does not exist on type 'typeof Listen'. as shown in the picture attached.

namespace CORE{
    export class Listen{
         commandsList:[RegExp, string, string];
         debugStyle:string;
         optionalParam:RegExp;
         optionalRegex:RegExp;
         namedParam:RegExp;
         splatParam:RegExp;
         escapeRegExp:RegExp;
        constructor(){
            this.commandsList = [];
            this.debugStyle = 'font-weight: bold; color: #00f;';
            this.optionalParam = /\s*\((.*?)\)\s*/g;
            this.optionalRegex = /(\(\?:[^)]+\))\?/g;
            this.namedParam    = /(\(\?)?:\w+/g;
            this.splatParam    = /\*\w+/g;
            this.escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#]/g;
        }

        public static commandToRegExp(command:string):RegExp{
            command = command.replace(this.escapeRegExp, '\\$&')
                    .replace(this.optionalParam, '(?:$1)?')
                    .replace(this.namedParam, function(match, optional) {
                        return optional ? match : '([^\\s]+)';
                    })
                    .replace(this.splatParam, '(.*?)')
                    .replace(this.optionalRegex, '\\s*$1?\\s*');

            return new RegExp('^' + command + '$', 'i');
        }

        public static registerCommand(command:RegExp, cb:string, phrase:string):void{
            this.commandsList.push({ command: command, callback: cb, originalPhrase: phrase });
        }

        public static addCommands(commands:string[]):void{
                  var cb;
                    for (var phrase in commands) {
                        if (commands.hasOwnProperty(phrase)) {
                            cb = this[commands[phrase]] || commands[phrase];
                            if (typeof cb === 'function') {
                                // convert command to regex then register the command
                                this.registerCommand(this.commandToRegExp(phrase), cb, phrase);
                            } else if (typeof cb === 'object' && cb.regexp instanceof RegExp) {
                                // register the command
                                this.registerCommand(new RegExp(cb.regexp.source, 'i'), cb.callback, phrase);
                            }
                        }
                    }
        }

        public static executeCommand(commandText:string):void{
            for (var j = 0, l = this.commandsList.length; j < l; j++) {
                var result = this.commandsList[j].command.exec(commandText);
                if (result) {
                    var parameters = result.slice(1);
                    // execute the matched command
                    this.commandsList[j].callback.apply(this, parameters);
                }
            }
        }        
    }
}

Answer 1

this doesn't exist on a static method. A static method is not tied to the class instance. There's a lot of reading on static methods, but basically: a class method can call a static method, a static method cannot call a class method (without an instance.)

The fix here is to remove static from your methods.