Contains: Java

java.lang.String provides a boolean method contains() that returns ‘true’ if a sequence of characters is found within the given string and ‘false’ otherwise Which word, “contains” or “contain,” should fill in the blank? Since we are referring to a single book in the third-person singular, we would use “contains.” Thus, the correct sentence is, “The book contains important information.” On the other hand, if we are talking about multiple books, we would use “contain.” Learn the meaning of contain as a verb in English, with different senses and usage. See how to use contain in sentences, with synonyms, antonyms, and related words. The contains() method in Java's String class offers a convenient solution for efficiently checking the existence of a substring within a given string.