find str in another str with regex - regex

Question

I defined:
var s1="roi john";
var s2="hello guys my name is roi levi or maybe roy";
i need to split the words in s1 and check if they contains in s2
if yes give me the specific exists posts
The best way to help me with this, it is makes it as regex, cause i need this checks for mongo db.
Please let me know the proper regex i need.
Thx.

Answer 1

Possibly was something that could be answered with just the regular expression (and is actually) but considering the data:
{ "phrase" : "hello guys my name is roi levi or maybe roy" }
{ "phrase" : "and another sentence from john" }
{ "phrase" : "something about androi" }
{ "phrase" : "johnathan was here" }
You match with MongoDB like this:
db.collection.find({ "phrase": /\broi\b|\bjohn\b/ })
And that gets the two documents that match:
{ "phrase" : "hello guys my name is roi levi or maybe roy" }
{ "phrase" : "and another sentence from john" }
So the regex works by keeping the word boundaries \b around the words to match so they do not partially match something else and are combined with an "or" | condition.
Play with the regexer for this.
Doing open ended $regex queries like this in MongoDB can be often bad for performance. Not sure of your actual use case for this but it is possible that a "full text search" solution would be better suited to your needs. MongoDB has full text indexing and search or you can use an external solution.
Anyhow, this is how you mactch your words using a $regex condition.
To actually process your string as input you will need some code before doing the search:
var string = "roi john";
var splits = string.split(" ");
for ( var i = 0; i < splits.length; i++ ) {
splits[i] = "\\b" + splits[i] + "\\b";
}
exp = splits.join("|");
db.collection.find({ "phrase": { "$regex": exp } })
And possibly even combine that with the case insensitive "$option" if that is what you want. That second usage form with the literal $regex operator is actually a safer form form usage in languages other than JavaScript.

Answer 2

using a loop to iterate over the words of s1 and checking with s2 will give the expected result
var s1="roi john";
var s2="hello guys my name is roi levi or maybe roy";
var arr1 = s1.split(" ");
for(var i=0;i<=arr1.length;i++){
if (s2.indexOf(arr1[i]) != -1){
console.log("The string contains "+arr1[i]);
}
}