// >> creating-listpicker-code
import { Component } from "@angular/core";
import { ListPicker } from "tns-core-modules/ui/list-picker";

let pokemonList = ["Bulbasaur", "Parasect", "Venonat", "Venomoth", "Diglett",
    "Dugtrio", "Meowth", "Persian", "Psyduck", "Arcanine", "Poliwrath", "Machoke"];

@Component({
    moduleId: module.id,
    templateUrl: "./creating-listpicker.component.html"
})
export class CreatingListPickerComponent {

    public pokemons: Array<string> = [];
    public picked: string;

    constructor() {
        for (let i = 0; i < pokemonList.length; i++) {
            this.pokemons.push(pokemonList[i]);
        }
    }

    public selectedIndexChanged(args) {
        let picker = <ListPicker>args.object;
        this.picked = this.pokemons[picker.selectedIndex];
    }
}
// << creating-listpicker-code

// >> creating-listpicker-code
import { Component } from "@angular/core";
import { ListPicker } from "tns-core-modules/ui/list-picker";

let pokemonList = ["Bulbasaur", "Parasect", "Venonat", "Venomoth", "Diglett",
    "Dugtrio", "Meowth", "Persian", "Psyduck", "Arcanine", "Poliwrath", "Machoke"];

@Component({
    moduleId: module.id,
    templateUrl: "./creating-listpicker.component.html"
})
export class CreatingListPickerComponent {

    public pokemons: Array<string> = [];
    public picked: string;

    constructor() {
        for (let pokemon of pokemonList) {
            this.pokemons.push(pokemon);
        }
    }

    public selectedIndexChanged(args) {
        let picker = <ListPicker>args.object;
        this.picked = this.pokemons[picker.selectedIndex];
    }
}
// << creating-listpicker-code

Change for loop to typescript for of loop
Change for loop to typescript for of loop

Change old simple for loop to typescript for of loop  
The for of loop is more readable and just better for this use case