I have a homework-related question.
I have an array of objects. One of the properties of each of these objects is a string. I need to be able to sort the array alphabetically with respect to this string. I have the sort function written; I've tested it with integers in place of the string. The sorting works fine. However, I don't know how to compare two strings alphabetically. How would I do this?
If you don't want to use existing string compare functions, try to use the ASCII values of each letter for comparison. For example, 'A' = 41 and 'B' = 42, so 'B' > 'A'
Thus, if you have 2 strings like
char str1[] = "abc";
char str2[] = "def";
you can compare them positionwise, so you may start first with something like
if(str1[0] < str2[0])
...
if(str1[1] < str2[1])
...
and so on. Of course, you can improve this through using a for or while loop
Related
I have a long string which contains only decimal numbers with two signs after comma
str = "123,457568,22321,5484123,77"
The numbers in string only decimals with two signs after comma. How I can separate them in different numbers like that
arr = ["123,45" , "7568,22" , "321,54" , "84123,77"]
You could try a regex split here:
str = "123,457568,22321,5484123,77"
nums = str.split(/(?<=,\d{2})/)
print nums
This prints:
123,45
7568,22
321,54
84123,77
The logic above says to split at every point where a comma followed by two digits precedes.
Scan String for Commas Followed by Two Digits
This is a case where you really need to know your data. If you always have floats with two decimal places, and commas are decimals in your locale, then you can use String#scan as follows:
str.scan /\d+,\d{2}/
#=> ["123,45", "7568,22", "321,54", "84123,77"]
Since your input data isn't consistent (which can be assumed by the lack of a reliable separator between items), you may not be able to guarantee that each item has a fractional component at all, or that the component has exactly two digits. If that's the case, you'll need to find a common pattern that is reliable for your given inputs or make changes to the way you assign data from your data source into str.
I have a string:
'my_array1: ["1445","374","1449","378"], my_array2: ["1445","374", "1449","378"]'
I need to match all sets of digits from my_array2: [...] and count how many of them there.
I need to do something like this with regex and ruby MatchData
string = 'my_array1: ["1445","374", "1449","378"], my_array2: ["1445","374", "1449","378"]'
matches = string.match(/my_array2\:\s[\[,]\"(\d+)\"/)
count_matches = matches.size
Expected result should be 4.
What is the correct way of doing it?
If you are guaranteed that the content of my_array2 is always numeric you could simply use split twice. First you splitby my_array2: [" and then split by ,. This should give you the amount of items you are after.
If you are not guaranteed that, you could still split by my_array2 and instead of splitting again, you use a pattern such as "\d+" (or "\d+(\.\d+)? if you have floating point values) and count.
An example of the expression is available here.
Sorry for this extreme beginner question. I have a string variable originaltext containing some multiline text. I can convert it into an array of lines like so:
lines = originaltext.split("\n");
But I need help sorting this array. This DOES NOT work:
lines.sort;
The array remains unsorted.
And an associated question. Assuming I can sort my array somehow, how do I then convert it back to a single variable with no separators?
Your only issue is a small one - sort is actually a method, so you need to call lines.sort(). In order to join the elements together, you can use the join() method:
var originaltext = "This\n\is\na\nline";
lines = originaltext.split("\n");
lines.sort();
joined = lines.join("");
Dim str as String
str = "30 40 50 60"
I want to count the number of substrings.
Expected Output: 4
(because there are 4 total values: 30, 40, 50, 60)
How can I accomplish this in VB6?
You could try this:
arrStr = Split(str, " ")
strCnt = UBound(arrStr) + 1
msgBox strCnt
Of course, if you've got Option Explicit set (which you should..) then declare the variables above first..
Your request doesn't make any sense. A string is a sequence of text. The fact that that sequence of text contains numbers separated by spaces is quite irrelevant. Your string looks like this:
30 40 50 60
There are not 4 separate values, there is only one value, shown above—a single string.
You could also view the string as containing 11 individual characters, so it could be argued that the "count" of the string would be 11, but this doesn't get you any further towards your goal.
In order to get the result that you expect, you need to split the string into multiple strings at each space, producing 4 separate strings, each containing a 2-digit numeric value.
Of course, the real question is why you're storing this value in a string in the first place. If they're numeric values, you should store them in an array (for example, an array of Integers). Then you can easily obtain the number of elements in the array using the LBound() and UBound() functions.
I agree with everything Cody stated.
If you really wanted to you could loop through the string character by character and count the number of times you find your delimiter. In your example, it is space delimited, so you would simply count the number of spaces and add 1, but as Cody stated, those are not separate values..
Are you trying to parse text here or what? Regardless, I think what you really need to do is store your data into an array. Make your life easier, not more difficult.
I have a string that
contains at least one number
can contain multiple numbers
Some examples are:
https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384
https://www.facebook.com/username_13/posts/101505775425651120
https://www.facebook.com/username/posts/101505775425699820
I need a way to extract the longest number from the string. So for the 3 strings above, it would extract
53199604568
101505775425651120
101505775425699820
How can I do this?
#get the lines first
text = <<ENDTEXT
https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384
https://www.facebook.com/username_13/posts/101505775425651120
https://www.facebook.com/username/posts/101505775425699820
ENDTEXT
lines = text.split("\n")
#this bit is the actual answer to your question
lines.collect{|line| line.scan(/\d+/).sort_by(&:length).last}
Note that i'm returning the numbers as strings here. You could convert them to numbers with to_i
parse the list (to get an int array), then use the Max function. array.Max for syntax.
s = "https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384"
s.scan(/\d+/).max{|a,b| a.length <=> b.length}.to_i