string-comparison

问题 In R, I have two character vectors, a and b. a <- c("abcdefg", "hijklmnop", "qrstuvwxyz") b <- c("abXdeXg", "hiXklXnoX", "Xrstuvwxyz") I want a function that counts the character mismatches between each element of a and the corresponding element of b. Using the example above, such a function should return c(2,3,1) . There is no need to align the strings. I need to compare each pair of strings character-by-character and count matches and/or mismatches in each pair. Does any such function exist

问题 In my python script, I have a list of strings like, birth_year = ["my birth year is *","i born in *","i was born in *"] I want to compare one input sentence with the above list and need a birth year as output. The input sentence is like: Example1: My birth year is 1994. Example2: I born in 1995 The output will be: Example1: 1994 Example2: 1995 I applied many approaches by using regex. But I didn't find a perfect solution for the same. 回答1: If you change birth_year to a list of regexes you

问题 In my python script, I have a list of strings like, birth_year = ["my birth year is *","i born in *","i was born in *"] I want to compare one input sentence with the above list and need a birth year as output. The input sentence is like: Example1: My birth year is 1994. Example2: I born in 1995 The output will be: Example1: 1994 Example2: 1995 I applied many approaches by using regex. But I didn't find a perfect solution for the same. 回答1: If you change birth_year to a list of regexes you

问题 I am curious why this is happening in PHP: '78' == ' 78' // true '78' == '78 ' // false I know that it's much better to use strcmp or the least === . I also know that when you compare numerical strings with == they are casted to numbers if possible. I also can accept that the leading space is ignored, so (int)' 78' is 78, and the answer is true in the first case, but I'm really confused why it's false in the second. I thought that '78' is casted to 78 and '78 ' is casted to 78 , too, so they

问题 I am curious why this is happening in PHP: '78' == ' 78' // true '78' == '78 ' // false I know that it's much better to use strcmp or the least === . I also know that when you compare numerical strings with == they are casted to numbers if possible. I also can accept that the leading space is ignored, so (int)' 78' is 78, and the answer is true in the first case, but I'm really confused why it's false in the second. I thought that '78' is casted to 78 and '78 ' is casted to 78 , too, so they

问题 I recently answered a SO-question about using -lt or -gt with strings. My answer was based on something I've read earlier which said that -lt compares one char from each string at a time until a ASCII-value is not equal to the other. At that point the result (lower/equal/greater) decides. By that logic, "Less" -lt "less" should return True because L has a lower ASCII-byte-value than l , but it doesn't: [System.Text.Encoding]::ASCII.GetBytes("Less".ToCharArray()) 76 101 115 115 [System.Text

问题 Consider a scenario where you are implementing code meant to be used for machine to machine communication. The typical example for that is the code executed inside a web API action method. Suppose that you want to perform an exact match between strings; maybe you have a list of users and you wan to find one specific user provided the user name: List<User> users = .... const string username = "user-123"; var user = users.Find(u => string.Equals(username, u.UserName)); In such a scneario should

问题 I want to compare ISO 8601 dates in javascript as strings instead of making Date objects for each string and comparing objects. var date_array = ['2012-10-01','2012-11-27','2012-12-23']; console.log(date_array[0] < date_array[1]) // gives true console.log(date_array[1] > date_array[2]) // gives false My reason for doing this is I believe string comparisons should be faster than making objects for each date string and comparing objects. These comparisons seem to work as expected in some

问题 I want to compare ISO 8601 dates in javascript as strings instead of making Date objects for each string and comparing objects. var date_array = ['2012-10-01','2012-11-27','2012-12-23']; console.log(date_array[0] < date_array[1]) // gives true console.log(date_array[1] > date_array[2]) // gives false My reason for doing this is I believe string comparisons should be faster than making objects for each date string and comparing objects. These comparisons seem to work as expected in some

问题 I'm fairly new to C programming, how would I be able to check that a string contains a certain character for instance, if we had: void main(int argc, char* argv[]){ char checkThisLineForExclamation[20] = "Hi, I'm odd!" int exclamationCheck; } So with this, how would I set exclamationCheck with a 1 if "!" is present and 0 if it's not? Many thanks for any assistance given. 回答1: By using strchr(), like this for example: #include <stdio.h> #include <string.h> int main(void) { char str[] = "Hi, I