Node dev : getNodeParameter usage?

Questions
12

Here an example which does exactly that:

import { IExecuteFunctions } from 'n8n-core';
import {
	INodeExecutionData,
	INodeType,
	INodeTypeDescription,
} from 'n8n-workflow';


export class Example implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Example',
		name: 'example',
		group: ['input'],
		version: 1,
		description: 'Example',
		defaults: {
			name: 'Example',
			color: '#0000FF',
		},
		inputs: ['main'],
		outputs: ['main'],
		properties: [
			{
				displayName: 'Age',
				name: 'age',
				type: 'number',
				default: 0,
			},
			{
				displayName: 'Brand Name',
				name: 'brandName',
				type: 'string',
				default: '',
			},
		]
	};


	execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {

		const items = this.getInputData();

		if (items.length === 0) {
			items.push({json: {}});
		}

		const returnData: INodeExecutionData[] = [];
		let item: INodeExecutionData;

		for (let i = 0; i < items.length; i++) {
			const age = this.getNodeParameter('age', i) as number | undefined;
			const brandName = this.getNodeParameter('brandName', i) as string | undefined;

			item = items[i];

			const newItem: INodeExecutionData = {
				json: {
					age: age || item.json.age,
					brandName: brandName || item.json.brandName,
				},
			};

			returnData.push(newItem);
		}

		return this.prepareOutputData(returnData);
	}
}

But that was really just an exception as we do not do free custom node development!

and which convention must follow the previous node to arrange these values in its ouput json ?

Again do not understand. There is simply no sorting in a JavaScript-Object.