What's the easiest way to find how many times every word appears in a string?

For ex. in : "Outside there are twelve birds,twelve cars and twelve trees".

Should I just search the string for the first whitespace,save the position,then exatract everything that was before the first whitespace,save it in a string,then delete everythign that was before the whitespace,after that search the string for that word,and everytime i find it,delete it(and increment an int in order to know how many times i found it)? Then repeat the process?

Is there a better way?

Is is possible to save everything word that the user inputs via console in a vector?

like:

for every word received as input,vector.push_back(word)

I thought about that,but I can't figure a way to take each word separately,I mean when the user writes a sentence and presses enter,all words will be received at once...

Store the words in a map of <string, int>. the first time you insert a word, store 1. If the word is already in the map, increment the integer.

It's even easier that that, because you don't even need special logic to handle the first insert. The map value constructs its content if the key is not present, and integers value initializes to zero, so just go ahead and increment at all times. Thus, just use the [] operator and increment it; if the key doesn't exist it is value initialized to zero before proceeding to increment it to one and everything is fine.

couldn't you ignore punctuation and do something like "if (input_string.contains("twelve") then ++twelve_counter"?

If you know your input precisely (and probably already know how many of each word).

Otherwise, you could easily catch words that appear in a longer, different word, resulting in erroneous counts.