Get recordId in LWC

Way 1

In js-meta.xml, set targets page

<isExposed>true<isExposed>

<targets>

    <target>lightning__RecordPage<target/>

</targets>

Then use @api to get recordId

import { LightningElement, api } from 'lwc';

export default class Sample extends LightningElement {

    @api recordId;

}

Way 2

Use CurrentPageReference

import { LightningElement, wire } from 'lwc';

import { CurrentPageReference } from 'lightning/navigation';

export default class Sample extends LightningElement {

    currentPageReference;

    @wire(CurrentPageReference)

    setCurrentPageReference(currentPageReference) {

        this.currentPageReference = currentPageReference;

        console.log('recordId: ' + this.currentPageReference.attributes.recordId);

    }

}