Is it possible to use LINQ to check if all numbers in a list are increasing monotonically?

Question

I\'m interested if there is a way, in LINQ, to check if all numbers in a list are increasing monotonically?

Example

List l         


        

Answer 1

Use a loop! It's short, fast and readable. With the exception of Servy's answer, most the solutions in this thread are unnecessarily slow (sorting takes 'n log n' time) .

// Test whether a sequence is strictly increasing.
public bool IsIncreasing(IEnumerable list)
{
    bool initial = true;
    double last = Double.MinValue;
    foreach(var x in list)
    {
        if (!initial && x <= last)
            return false;

        initial = false;
        last = x;
    }

    return true;
}

Examples

1. IsIncreasing(new List{1,2,3}) returns True
2. IsIncreasing(new List{1,3,2}) returns False