export default class StringBuilder {
    public constructor(private value: string = '') {

    }
    public append(s: string | number): StringBuilder {
        if (typeof s === 'string') {
            this.value += s.toString();
        } else {
            this.value += String.fromCharCode(s);
        }
        return this;
    }

    public length(): number {
        return this.value.length;
    }

    public charAt(n: number): string {
        return this.value.charAt(n);
    }

    public deleteCharAt(n: number) {
        this.value = this.value.substr(0, n) + this.value.substring(n + 1);
    }

    public setCharAt(n: number, c: string) {
        this.value = this.value.substr(0, n) + c + this.value.substr(n + 1);
    }

    public toString(): string {
        return this.value;
    }
}