Your «indexOf» example should use >= 0, not > 0, since 0 is valid if the substring occurs at the beginning of the string. (Doesn’t in your example, but could in other cases.) Added this response since people are obviously still searching and finding this answer.
In Java, how do I check if a string contains a substring (ignoring case)? [duplicate] 6 answers For example: String st = «sometinganimalcouch»; String st2 = «something»; In Java, how do I check if a string contains a substring (ignoring case)? Related. 5578. What is the difference between String and string in C#? 1867.
I also favor the RegEx solution. The code will be much cleaner. I would hesitate to use toLowerCase() in situations where I knew the strings were going to be large, …
But calling toUpperCase() on a large String (several thousands characters) may have a negative impact on memory usage. This is one of those cases where you must make a trade off between better speed (toUpperCase(), contains()) and less memory . If this operation is needed many times reusing a Pattern object may even be better.
Oct 13, 2016 · The third method you can use to check if one String contains another in Java is contains() method of String. This method returns true if a substring is present in String, or false otherwise. The only difference between contains() and indexOf() is that former …
Some time you want to check if one String contains another String or SubString or not e.g. «HelloWorld» contains «Hello» and «World» SubString. There are many ways to check SubString in String in Java e.g. contains(), indexOf() or matches() method of java.lang.String class.
(Also, remember that when you use the matches method, your regex pattern must match the entire string.) Here’s the source code for a complete Java program that demonstrates this case-insensitive pattern matching technique: /** * Demonstrates how to perform a case-insensitive pattern * match using String and the String.matches() method.
Ignoring running time of built-in functions. Best case : you have a hit right on the first go with i=0, then you will only have to do L2 iterations, this is the lower bound. Worst case: you have to check across all the L1-L2 search space, in which case you will be doing L2 iterations for each consecutive search. So upper bound will be (L1-L2)*L2, ignoring the effect of L2^2 compared to L1*L2
How to check if a String contains another String in a case insensitive manner in Java? 17 answers I have two String s, str1 and str2 . How do I check if str2 is contained within str1 , ignoring case?
Searching a character in the String. indexOf(char c): It searches the index of specified character within a given string.It starts searching from beginning to the end of the string (from left to right) and returns the corresponding index if found otherwise returns -1.
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str.contains(null); Java String contains() method Example. The second print statement displayed false because the contains() method is case sensitive. You can also use the contains() method for case insensitive check, I have covered this at the end of this tutorial.