I created a Java program to compare two strings:
String str = "Hello";
if (str.equals("hello")) {
System.out.println("match");
} else {
System.out.println("no match");
}
It's case-sensitive. How can I change it so that it's not?
How do I make my string comparison case-insensitive?
Viewed 307658
12 Answers
The best way is to use str.equalsIgnoreCase("foo"). It's optimized specifically for this purpose.
You can also convert both strings to upper- or lowercase before comparing them with equals. This is a trick that's useful to remember for other languages which might not have an equivalent of equalsIgnoreCase.
str.toUpperCase().equals(str2.toUpperCase())
If you are using a non-Roman alphabet, take note of this part of the JavaDoc of equalsIgnoreCase which says
Note that this method does not take locale into account, and will result in unsatisfactory results for certain locales. The Collator class provides locale-sensitive comparison.
Use String.equalsIgnoreCase().
Use the Java API reference to find answers like these:
Use s1.equalsIgnoreCase(s2): https://docs.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#equalsIgnoreCase(java.lang.String).
public boolean newEquals(String str1, String str2)
{
int len = str1.length();
int len1 = str2.length();
if(len==len1)
{
for(int i=0,j=0;i<str1.length();i++,j++)
{
if(str1.charAt(i)!=str2.charAt(j))
return false;
}`enter code here`
}
return true;
}
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