What is the easiest way to check if a string exist in 2 array? p/s Is there is LINQ method to replace this?
// Old school method
bool result = false;
var stringArray1 = new string[] { "ABC", "EFG", "HIJ" };
var stringArray2 = new string[] {"123", "456", "ABC"};
for (var i = 0; i < stringArray1.Count; i++) {
var value1 = stringArray1[i];
for (var j = 0; j < stringArray2.Count; j++) {
var value2 = stringArray2[j];
if(value1 == value2)
result = true;
}
}
For a case sensitive search, you can just do this
var result = stringArray1.Any(x => stringArray2.Contains(x));
As answered Intersect does the the job very well too.
Though if you want a more robust culturally insensitive version
You could use
var culture = new CultureInfo("en-US");
var result = stringArray1.Any(x =>
stringArray2.Any(y =>
culture.CompareInfo.IndexOf(x, y, CompareOptions.IgnoreCase) >= 0));
Where culture is the instance of CultureInfo describing the language that the text is written in
You could intersect the two arrays and then check if there any items in the result:
var stringArray1 = new string[] { "ABC", "EFG", "HIJ" };
var stringArray2 = new string[] { "123", "456", "ABC" };
var result = stringArray1.Intersect(stringArray2).Any();
If you care case sensitivity, you can pass a StringComparer as the second argument of Intersect. For example:
var result = stringArray1.Intersect(stringArray2, StringComparer.OrdinalIgnoreCase).Any();
Any calls is faster than O(n+m) .Intersect... just sayingHashSet and do var d = new HashSet<string>(stringArray2); var result = stringArray1.Any(s => d.Contains(s)); instead to remove *m in time complexity... Also indeed even O(m*n) solution is fine, especially if arrays are normally close enough so cost of constructing hashsets is not justified as basic iteration ends early enough.
iis used twice