我想使用c#检查字符串值是否包含字符串数组中的单词。例如,
string stringToCheck = "text1text2text3";
string[] stringArray = { "text1", "someothertext", etc... };
if(stringToCheck.contains stringArray) //one of the items?
{
}
我如何检查字符串值'stringToCheck'是否包含数组中的一个词?
我想使用c#检查字符串值是否包含字符串数组中的单词。例如,
string stringToCheck = "text1text2text3";
string[] stringArray = { "text1", "someothertext", etc... };
if(stringToCheck.contains stringArray) //one of the items?
{
}
我如何检查字符串值'stringToCheck'是否包含数组中的一个词?
当前回答
演示了三个选项。我认为第三条是最简洁的。
class Program {
static void Main(string[] args) {
string req = "PUT";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("one.1.A"); // IS TRUE
}
req = "XPUT";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("one.1.B"); // IS TRUE
}
req = "PUTX";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("one.1.C"); // IS TRUE
}
req = "UT";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("one.1.D"); // false
}
req = "PU";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("one.1.E"); // false
}
req = "POST";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("two.1.A"); // IS TRUE
}
req = "ASD";
if ((new string[] {"PUT", "POST"}).Any(s => req.Contains(s))) {
Console.WriteLine("three.1.A"); // false
}
Console.WriteLine("-----");
req = "PUT";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("one.2.A"); // IS TRUE
}
req = "XPUT";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("one.2.B"); // false
}
req = "PUTX";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("one.2.C"); // false
}
req = "UT";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("one.2.D"); // false
}
req = "PU";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("one.2.E"); // false
}
req = "POST";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("two.2.A"); // IS TRUE
}
req = "ASD";
if (Array.IndexOf((new string[] {"PUT", "POST"}), req) >= 0) {
Console.WriteLine("three.2.A"); // false
}
Console.WriteLine("-----");
req = "PUT";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("one.3.A"); // IS TRUE
}
req = "XPUT";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("one.3.B"); // false
}
req = "PUTX";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("one.3.C"); // false
}
req = "UT";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("one.3.D"); // false
}
req = "PU";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("one.3.E"); // false
}
req = "POST";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("two.3.A"); // IS TRUE
}
req = "ASD";
if ((new string[] {"PUT", "POST"}.Contains(req))) {
Console.WriteLine("three.3.A"); // false
}
Console.ReadKey();
}
}
其他回答
你可以定义自己的string.ContainsAny()和string.ContainsAll()方法。作为奖励,我甚至还抛出了一个string.Contains()方法,该方法允许不区分大小写的比较等等。
public static class Extensions
{
public static bool Contains(this string source, string value, StringComparison comp)
{
return source.IndexOf(value, comp) > -1;
}
public static bool ContainsAny(this string source, IEnumerable<string> values, StringComparison comp = StringComparison.CurrentCulture)
{
return values.Any(value => source.Contains(value, comp));
}
public static bool ContainsAll(this string source, IEnumerable<string> values, StringComparison comp = StringComparison.CurrentCulture)
{
return values.All(value => source.Contains(value, comp));
}
}
你可以用下面的代码进行测试:
public static void TestExtensions()
{
string[] searchTerms = { "FOO", "BAR" };
string[] documents = {
"Hello foo bar",
"Hello foo",
"Hello"
};
foreach (var document in documents)
{
Console.WriteLine("Testing: {0}", document);
Console.WriteLine("ContainsAny: {0}", document.ContainsAny(searchTerms, StringComparison.OrdinalIgnoreCase));
Console.WriteLine("ContainsAll: {0}", document.ContainsAll(searchTerms, StringComparison.OrdinalIgnoreCase));
Console.WriteLine();
}
}
⚠️ Note: this does not answer the question asked |
---|
The question asked is "how can I check if a sentence contains any word from a list of words?" |
This answer checks if a list of words contains one particular word |
stringArray.ToList().Contains(stringToCheck)
如果stringArray包含大量不同长度的字符串,可以考虑使用Trie存储和搜索字符串数组。
public static class Extensions
{
public static bool ContainsAny(this string stringToCheck, IEnumerable<string> stringArray)
{
Trie trie = new Trie(stringArray);
for (int i = 0; i < stringToCheck.Length; ++i)
{
if (trie.MatchesPrefix(stringToCheck.Substring(i)))
{
return true;
}
}
return false;
}
}
下面是Trie类的实现
public class Trie
{
public Trie(IEnumerable<string> words)
{
Root = new Node { Letter = '\0' };
foreach (string word in words)
{
this.Insert(word);
}
}
public bool MatchesPrefix(string sentence)
{
if (sentence == null)
{
return false;
}
Node current = Root;
foreach (char letter in sentence)
{
if (current.Links.ContainsKey(letter))
{
current = current.Links[letter];
if (current.IsWord)
{
return true;
}
}
else
{
return false;
}
}
return false;
}
private void Insert(string word)
{
if (word == null)
{
throw new ArgumentNullException();
}
Node current = Root;
foreach (char letter in word)
{
if (current.Links.ContainsKey(letter))
{
current = current.Links[letter];
}
else
{
Node newNode = new Node { Letter = letter };
current.Links.Add(letter, newNode);
current = newNode;
}
}
current.IsWord = true;
}
private class Node
{
public char Letter;
public SortedList<char, Node> Links = new SortedList<char, Node>();
public bool IsWord;
}
private Node Root;
}
如果stringArray中的所有字符串都具有相同的长度,那么使用HashSet而不是Trie会更好
public static bool ContainsAny(this string stringToCheck, IEnumerable<string> stringArray)
{
int stringLength = stringArray.First().Length;
HashSet<string> stringSet = new HashSet<string>(stringArray);
for (int i = 0; i < stringToCheck.Length - stringLength; ++i)
{
if (stringSet.Contains(stringToCheck.Substring(i, stringLength)))
{
return true;
}
}
return false;
}
⚠️ Note: this does not answer the question asked |
---|
The question asked is "how can I check if a sentence contains any word from a list of words?" |
This answer checks if a list of words contains one particular word |
最简单最简单的方法:
bool bol = Array.Exists(stringarray, E => E == stringtocheck);
也许是这样的:
string stringToCheck = "text1text2text3";
string[] stringArray = new string[] { "text1" };
if (Array.Exists<string>(stringArray, (Predicate<string>)delegate(string s) {
return stringToCheck.IndexOf(s, StringComparison.OrdinalIgnoreCase) > -1; })) {
Console.WriteLine("Found!");
}