Angular中如何用Lambda表达式替换双重循环简化代码？

Sure thing! You can replace those nested for loops with a much cleaner approach using Array.filter() and Array.includes()—leveraging arrow functions (lambdas) exactly as you wanted. Here's the refactored code:

this.markersDisplay = this.markersSource; // Start with all markers
if (this.isValid(this.selectedMarkersType)) {
  // Filter markers where MarkerType is in the selected list
  this.markersDisplay = this.markersSource.filter(marker => 
    this.selectedMarkersType.includes(marker.MarkerType)
  );
}

How this compares to your original code: #

• filter() iterates over each marker in markersSource and keeps only the ones that pass our condition, replacing your outer loop entirely.
• includes() checks if the current marker's MarkerType exists in selectedMarkersType—this handles the inner loop and the break logic (since includes() stops searching as soon as it finds a match).
• The core logic is identical to your original code, but it’s far more concise and easier to read at a glance.

This follows modern TypeScript/JavaScript best practices and cuts out all the loop boilerplate. It’s a standard pattern for filtering items based on membership in another array.

内容的提问来源于stack exchange，提问作者Nemanja Andric