Add Dropdown (Picklist) in Lightning Web Component.

In Aura Components we can use lightning-select to create dropdown. In Lightning Web Component there is a lightning-combobox component that allows to do this.

Here is example on how to do this in LWC:

LightningDropDown.html

LightningDropDown.js

import { LightningElement, track } from 'lwc';

export default class LightningDropDown extends LightningElement {
@track selectedColor = 'white';

get colorOptions() {
    return [
             { label: 'White', value: 'white' },     
             { label: 'Red', value: 'red' },
             { label: 'Green', value: 'green' },
             { label: 'Blue', value: 'blue' },
           ];
}

handleChange(event) {
        this.selectedColor = event.detail.value;
     }
}