CODEWITHSUNDEEP
c#
Saravanan
Saravanan

Reputation: 11592

String Equals() method fails even though the two strings are same in C#?

I want to compare whether two strings are equal or not in C# using the Equals() method of the string class. But even though both strings are same, my conditional check is failing.

I have seen that both strings are equal and also verified this at the http://text-compare.com/ site. I don't know what is the issue here...

My code is :

protected string getInnerParaOnly(DocumentFormat.OpenXml.Wordprocessing.Paragraph currPara, string paraText)
        {
            string currInnerText = "";
            bool isChildRun = false;

        XmlDocument xDoc = new XmlDocument();
        xDoc.LoadXml(currPara.OuterXml);
        XmlNode newNode = xDoc.DocumentElement;

        string temp = currPara.OuterXml.ToString().Trim();

        XmlNodeList pNode = xDoc.GetElementsByTagName("w:p");
        for (int i = 0; i < pNode.Count; i++)
        {
            if (i == 0)
            {
                XmlNodeList childList = pNode[i].ChildNodes;
                foreach (XmlNode xNode in childList)
                {
                    if (xNode.Name == "w:r")
                    {
                        XmlNodeList childList1 = xNode.ChildNodes;
                        foreach (XmlNode xNode1 in childList1)
                        {
                            if (xNode1.Name == "w:t" && xNode1.Name != "w:pict")
                            {
                                currInnerText = currInnerText + xNode1.InnerText;
                            }
                        }
                    }
                }
              if (currInnerText.Equals(paraText))
              {
                  //do lot of work here...
              }
   }
}

When I put a break point in and go through step by step, watching each and every character, then there is a difference in currInnerText last index. It looks like an empty char. But I already used the Trim() function. This is the picture captured during the debug process.

What is the solution for removing the empty char or any other spurious characters at the end of the currInnerText string?

enter image description here

Upvotes: 27

Views: 32617

Answers (5)

James L.
James L.

Reputation: 14515

In addition to using characters that look like other characters, but are actually different, this can occur when using Reflection. Reflection boxes the values twice into new objects and == will compare by reference. Try using object.Equals(currentValue, newValue) instead.

Upvotes: 1

Ahmad
Ahmad

Reputation: 9658

In my case, the difference was different encoding of space character, one string contained non-breaking space (160) and the other one contained normal space (32)

it can be solved by

string text1 = "String with non breaking spaces.";
text1 = Regex.Replace(text1, @"\u00A0", " ");
// now you can compare them

Upvotes: 14

aquinas
aquinas

Reputation: 23786

Before you call .Equals, try this:

if (currInnerText.Length != paraText.Length)
    throw new Exception("Well here's the problem");

for (int i = 0; i < currInnerText.Length; i++) {
    if (currInnerText[i] != paraText[i]) {
        throw new Exception("Difference at character: " + i+1);
    }
}

That should throw an exception if Equals returns false and should give you an idea what's going.

Upvotes: 8

Stefan P.
Stefan P.

Reputation: 9519

Try this

String.Equals(currInnerText, paraText, StringComparison.InvariantCultureIgnoreCase);

Upvotes: 30

Cristi M
Cristi M

Reputation: 446

Try putting a breakpoint and checking the length. Also, in some cases, if the locale is not the same, the equals function does not result in true. Another method you could try(checking the length) is printing both like this ---string1---, ---string2---, this way, you could see if you have any trailing spaces. To fix this you can use string1.trim()

Upvotes: 13

Related Questions