optimizing the if and foreach for nullchecks

Question

Anyway to optimize this code for null checks?

if (objA != null && objA .Length > 0)
            {
                foreach (var child in objA )
                {
                    if (child.Any != null)
                    {
                        foreach (var a in child.Any)
                        {
                            if (a.Name.ToLower() == "code")
                            {
                                //some code
                            }
                        }
                    }
                }
            }

You can safely lose `objA.Length > 0`, as the `foreach` loop will effectively duplicate it. Not seeing anything else. — glenebob, Apr 30 '18 at 04:11
What is the type of `objA`? Please show us the definition of your `Any` property. — mjwills, Apr 30 '18 at 04:15
`foreach (var a in objA?.SelectMany(z => z?.Any).Where(y => y?.Name?.ToLower() == "code") ?? Enumerable.Empty())` would likely work. — mjwills, Apr 30 '18 at 04:19
Optimisation wise, what is your aim? Do you want clarity? Performance? Brevity? Something else? — mjwills, Apr 30 '18 at 04:23

Jeremy Thompson · Accepted Answer · 2018-05-02T08:57:19.337

I think you want to use the C# 6 null condition ? operator . Here is some psuedo code:

for (int i = 0; i < objA?.Length; i++)
{
    ExecuteCode(objA[i]?.Any);
}

...

static void ExecuteCode(YourTypeHere[] children)
{
    for (int i = 0; i < children?.Length; i++)
    {
        if (children[i]?.Name?.ToLower() == "code")
        {
            //some code
        }
    }
}

Using a for loop is faster than a foreach: In .NET, which loop runs faster, 'for' or 'foreach'?. Both loops are slightly faster than Linq.

optimizing the if and foreach for nullchecks

1 Answers1