"search string" - This searches for any string that contains what is in between the quotations. So it would return "search string" and it would also return "This is my search string" but it would not return "Search my string" because the actual phrase "search string" is not in our last example.
Putting something between two quotations is basic to all searches. Now we are going to start adding in symbols to our searches. Each of these symbols adds a different meaning to what is contained within our quotes. These help you do a more targeted and precise search than just finding a chain of characters.
"^Happy" - By adding the caret you are now asking to search for a string that starts with whatever is contained within the quotes. So this would return "Happy" or "Happy Birthday" but it would not return "I am happy" because happy is not the first word.
"the end$" - By adding a dollar sign at the end of our search string, you are saying you want a string that end's with your search term. This search would return "the end" and would also return "my only friend, the end" but would not return "the end is near."
"^boys$" - In this example we are adding both the caret to the beginning and the dollar sign to the end. This means it is looking for a string that both begins and ends with our search. This would return "Boys" and would also return "Boys will be boys" but it would not return "Boys will be men" or "toys for boys" because the search term is not both the first and last thing in the string.
"hello|hi" - In this example two words "hello" and "hi" are separated by a vertical line. This means it is searching for either of these terms. So it would return "hello, how are you today" or "hi, what are you doing" or even "hello" or "hi".
"a{3}" - this is searching for the character "a" repeated three times. So it would return strings that contained "aaa". It would not return "a" or even "aa".
"ab{3}" - means that you are looking for a followed by three b's, or "abbb"
"ab{4,6}" - this means a followed by 4, 5 or 6 b's. So abbbb or abbbbb or abbbbbb.
"a." - the period indicates a single character. So a. would mean a followed by another character. In this example "an" would be returned, however "a3" would not.
"[ab]" - this is looking for a string that has a or b in it. You could also write this as "a|b"
"[a-d]" - this is looking for a string that has a, b, c, or d in it. It could also be written as "a|b|c|d"
"[a-z]" - looking for a string with any lower case letter in it.
"[A-Z]" - looking for a string with any upper case letter in it.
"[a-zA-Z]" - looking for a string with any letter of either case in it.
"[0-9]%" - looking for a number followed by a percentage sign.
Although there are many more regular expressions that exist, this list is hopefully easy enough to understand and will help get you started.
