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Learn how to effectively exclude null values from your arrays when using *ngFor in Angular for cleaner outputs.
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How to Skip Printing Null Elements in an Array During *ngFor in Angular

If you are working with Angular and dealing with arrays, you may encounter the issue of printing unwanted null or empty elements. This is especially prevalent when retrieving data from a database, where some entries might not have complete information, leading to awkward blank spaces in your UI. If you want to ensure that your application remains tidy and professional, here's how you can skip printing null elements in an array during the *ngFor directive.

The Problem: Printing Null Elements

You might find yourself grappling with the following scenario:

You have an array containing various objects, each having properties like title, paragraph1, paragraph2, etc.

Some objects might have empty properties (e.g., paragraph2 is null or undefined), which result in unwanted blank spaces when displayed on the screen.

You want to avoid showing any empty entries to keep your interface clean and user-friendly.

Example of Unwanted Output

Suppose your Angular code looks something like this:

[[See Video to Reveal this Text or Code Snippet]]

If any trees object is missing paragraph2, you might see an undesirable blank space where it should be.

The Solution: Filtering Out Nulls in the Component

Instead of solely relying on *ngIf to hide null elements, you can preprocess your array data in the component using the filter() method. This approach ensures that the view only receives the data you want to display. Here are the steps you need to follow:

Step 1: Filter Out Null Values in TypeScript

In your component.ts file, you can create a filtered version of your array like this:

[[See Video to Reveal this Text or Code Snippet]]

This code snippet effectively removes all null elements from your array. You would replace arr1 with your specific data array and filter out unwanted properties based on your criteria.

Step 2: Utilize the Clean Array in the Template

Now that you have a clean version of your array (let's call it filteredTrees), you can simply iterate over it in your template:

[[See Video to Reveal this Text or Code Snippet]]

Key Points to Remember

Preprocess Data: Handling the filtering in the TypeScript component rather than the template separates logic from presentation, reducing clutter and complexity.

Dynamic Rendering: Use *ngIf in the template for any specific property you want to selectively render. This approach can further enhance your presentation layer.

Conclusion

By filtering out null values from your arrays in Angular before binding them to the view, you can effectively skip printing unwanted empty elements. This not only enhances the user experience by providing a clean interface but also maintains a clear separation between your data logic and presentation.

Implement these tactics in your Angular application to keep your layout organized and professional-looking. With a little preprocessing, you can ensure a seamless experience for your users without the visual distraction of null or empty elements.