declare global {
	interface Array<T> {
		randomItem: () => T;
		randomIndex: () => number;
		last: () => T;
	}
	
	interface ReadonlyArray<T> {
		randomItem: () => T;
		randomIndex: () => number;
		last: () => T;
	}
	
	interface String {
		capitalize: () => string;
	}
}

const extendArray = () => {
	Array.prototype['randomItem'] = function() {
		return this[Math.floor(Math.random()*this.length)];
	}
	
	Array.prototype['randomIndex'] = function() {
		return Math.floor(Math.random()*this.length);
	}
	
	Array.prototype['last'] = function() {
		return this[this.length - 1];
	}
}

const extendString = () => {
	String.prototype['capitalize'] = function() {
		return this.charAt(0).toUpperCase() + this.slice(1);
	}
}

export const install = () => {
	extendArray();
	extendString();
}