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C# Developers: Stop Using foreach for Large Arrays (Use This Instead)
Span<T> — the memory-efficient loop alternative that cuts processing time by 70% with zero garbage collection overhead
Most C# developers write loops the same way they learned years ago. They reach for foreach without considering the performance implications, especially when processing large datasets or performance-critical applications. Modern C# offers significantly faster alternatives that can reduce execution time by up to 90% in memory-intensive operations.
First, foreach Loops
Traditional foreach Loops are good, but they actually carry some costs that are compounded by scale. When iterating over collections, each iteration involves method calls, interface dispatching, and potential memory allocations. For collections containing millions of elements, these microscopic costs become measurable issues.
Consider this common pattern for processing numerical data:
// has some performance costs
var numbers = new int[1000000];
var…
