If I want to compare the amount one word is used to the other, how would I do that?
It wouldn't be str.contains("cat") > str.contains("dog")
So for example:
if(str.contains("cat") == str.contains("dog")){
System.out.println("true");
}
else
system.out.print("false");
This would hypothetically print true if cat and dog appear the same amount of times. But obviously it doesn't, what would I have to d, to get it to check?
String#contains() will return true if the searched string is found at least once, which is done for performance reasons. Thus str.contains("cat") == str.contains("dog") would be true if both cat and dog are found independent of how often they are found.
What you could do is use 2 regular expressions and check the number of matches:
int countWords(String input, String word ) {
Pattern p = Pattern.compile( "\\b" + word + "\\b" );
int count = 0;
Matcher m = p.matcher( input );
while( m.find() ) {
count++;
}
return count;
}
Usage:
String str = "dog eats dog but cat eats hotdog";
System.out.println("dogs: " + countWords( str, "dog"));
System.out.println("cats: " + countWords( str, "cat"));
Output:
dogs: 2
cats: 1
To count number of ocurrences of a String in another String create a function (extracted from here):
The "split and count" method:
public class CountSubstring {
public static int countSubstring(String subStr, String str){
// the result of split() will contain one more element than the delimiter
// the "-1" second argument makes it not discard trailing empty strings
return str.split(Pattern.quote(subStr), -1).length - 1;
}
The "remove and count the difference" method:
public static int countSubstring(String subStr, String str){
return (str.length() - str.replace(subStr, "").length()) / subStr.length();
}
Then you just have to compare:
return countSubstring("dog", phrase) > countSubstring("cat", phrase);
ADDITIONAL INFORMATION
To compare strings use String::equals or String::equalsIgnoreCase if you don't mean uppercase and lowercase.
string1.equals(string2);
string1.equalsIgnoreCase(string2);
To find number of ocurrences of a string in another string use indexOf
string1.indexOf(string2, index);
To see if a string contains another string use contains
string1.contains(string2);
There are many possible solutions for your problem. I won't show you a full solution, but will try to guide you. Here are some:
split the String according to space(s), iterate over the resulted array and increment the counter when you match the String you're looking for.
use a regex that matches exactly the word you're looking for, there are many useful methods in the Matcher and Pattern classes, go through them.
Java 8 Stream tools has countless methods, you can get the result in one line.
You could get the count in the following way for dog
index = -1;
dogcount = 0;
do {
index = str.indexOf("dog",index+1);
if(index > -1)
dogcount++;
}while(index == -1);
similarly get cat count
Use Apache Commons StringUtils.CountMatches: - counts the number of occurrences of one String in another
