The strcmp function takes two input arguments two strings and returns either true or false, just like any boolean expression. Strings str1 and str2 are not identical, so invoking strcmp returns logical 0. For caseinsensitive text comparison, use strcmpi instead of strcmp. If statement comparing strings matlab answers matlab central. Note that strcmp can be use with not string inputs, in this case matlab returns 0. Tf is 1 because both character vectors start with the characters he. The function strcmp is used when comparing two strings for equality in matlab. Text is considered identical if the content of each is the same up to the end or the. Determine array equality matlab isequal mathworks deutschland. Note that the value returned by strcmp is not the same as the c language convention. That file was not part of the compilation database. Comparing strings with and without matlab answers matlab.
If statement comparing strings matlab answers matlab. Why dont we use to compare strings in matlab stack. Learn more about if statement, strings, compare, eq error. Strings str1 and str2 are not identical, so invoking strcmp returns. Note that the matlab strcmp differs from the c version of strcmp. When used to compare numeric data, strcmp returns logical 0. In addition, the strcmp function is case sensitive. I want to compare each of those strings with a cell, and if the cell does not match any of the strings in the array, i want to delete it. If pattern is not found, then strfind returns an empty array. Return 1 if the character strings s1 and s2 are the same, disregarding case of alphabetic characters, and 0 otherwise. A b returns a logical array with elements set to logical 1 true where arrays a and b are equal. Choose a web site to get translated content where available and see local events and offers.
For compatibility with matlab, octaves strcmp function returns 1 if the character strings are equal, and 0 otherwise. To test if two strings are equivalent, use strcmp, which allows vectors of. For more information, see compare function handles isequal returns logical 0 false for two objects with dynamic properties, even if the properties have the same names and values. Feb 21, 2017 regardless, given the approach you have followed, if x is equal to a, then the second half of the clause will be true, even though the first part of the clause is false. Mathworks is the leading developer of mathematical computing. Jan 12, 2017 this gives me a 5x3 logical array, but is there a way to do it without calling each column individually. Numeric or string inputs a and b must either be the same size or have sizes that are compatible for example, a is an mbyn matrix and b is a scalar or 1byn row vector. I wrote a simple program to learn about sub functions in matlab. The problem now is, that sometimes the strcmp works and sometimes not. The strcmp function is intended for comparison of text. I know i can find the number by using length, but i can not do something like. I have a variable number of strings stored in an array. The strcmpi function is intended for comparison of text.
You can compare individual characters in two strings for equality. The strfind function executes a casesensitive search. Follow 59 views last 30 days liu james on 2 jul 2017. Based on your location, we recommend that you select.
My advice is to write the forloop using separate lines rather than forcing it into a single line. The output, k, indicates the starting index of each occurrence of pattern in str. Follow 57 views last 30 days liu james on 2 jul 2017. Also note how i replaced the quote character with the empty string to make the strcmp return true for both versions. String comparisons may also be performed with the strcmp function, not with the comparison operators listed above. Use this knowledge to find if num is both a positive number and not equal to 1.
In the nickscellarray is at the end for example two times the user abccrusso, one time with the counter on 3 and one time with the counter on 5. An expression is true when its result is nonempty and contains only nonzero elements logical or real numeric. For compatibility with matlab, octaves strncmpi function returns 1 if the character strings are equal, and 0 otherwise. The original poster indicated that the values are strings. Although strcmp shares a name with a c function, it does not follow the c language convention of returning 0 when the text inputs match. Cant use strcmp with two strings or char values that are apparently equal. Determine inequality matlab ne mathworks united kingdom. I have two identical string matrices see attached mat file but dont know why strcmp below returns 0 while i was expecting one. Compare the first two characters with the strncmp function. Regardless, given the approach you have followed, if x is equal to a, then the second half of the clause will be true, even though the first part of the clause is false. Operands, specified as scalars, vectors, matrices, or multidimensional arrays.
Compare strings case insensitive matlab strcmpi mathworks. The other argument may also be a cell array of strings of the same size or with only one element, char matrix or character string. Strcmp will only return true if every character of both strings is the same and they are the same length. The test compares both real and imaginary parts of numeric arrays. This matlab function compares s1 and s2, ignoring any differences in letter case. See the input arguments section for a definition of equivalence for each data type. If used on unsupported data types, strcmp always returns 0. For storing string on ptr you need to allocate memory using malloc like. This code is iterated over every line within the logfile. Mathworks is the leading developer of mathematical computing software for engineers. The c version of strcmp returns 0 when two character arrays are the same, not when they are different. If strcmp returned 1 true for equal strings and 0 false for inequal ones, it would be impossible to use it to obtain the degree or direction of inequality i. This matlab function compares s1 and s2 and returns 1 true if the two are identical and 0 false.
Although strcmpi shares a name with a c function, it does not follow the c language convention of returning 0 when the text inputs match. Strings str1 and str2 are not identical, so invoking strcmp returns logical 0 false. Nan not a number, nat not a time, undefined categorical elements, and values are considered to be unequal to other elements, as well as themselves. The operator behaves differently than the function strcmp in matlab. Generated on 2019mar30 from project glibc revision glibc2. If you do not get the expected result, the inputs differ from what you think they are. For casesensitive text comparison, use strcmp instead of strcmpi. Text is considered identical if the content of each is the same up to the end or the first n characters, whichever comes first. This is consistent with the ordering used by max, min and sort, but is not consistent with matlab, which only compares the real parts. If you attempt to compare two strings using and the strings are not the same length, then you will get errors. String comparisons can be a good deal slower at least in current. See strings eq x, y return true if the two inputs are equal. For compatibility with matlab, octaves strncmp function returns 1 if the character strings are equal, and 0 otherwise. Strings are considered identical when they have the same size and content.
The equality of two function handles depends on how they are constructed. This is consistent with the ordering used by max, min and sort, but is not consistent with matlab, which only compares the real parts string comparisons may also be performed with the strcmp function, not with the comparison operators listed above. In matlab or c, when comparing strings which are just arrays of characters you. This is just the opposite of the corresponding c library function. According to the matlab documentation you need to use strcmp to compare strings for. Unlike in natural language, you have to write out a complete comparison on both sides of the boolean operators, thats how it works.
Determine array equality matlab isequal mathworks italia. And you can use cell inputs to easily compare multiple strings which is useful. A b returns a logical array with elements set to logical 1 true where arrays a and b are not equal. Although strncmp shares a name with a c function, it does not follow the c. Index into str1 to extract the elements that do not match gemini. For caseinsensitive text comparison, use strcmpi instead of strcmp although strcmp shares a name with a c function, it does not follow the c language convention of returning 0 when the text inputs match with string arrays, you can use relational operators. Execute statements if condition is true matlab if elseif. Cant use strcmp with two strings or char values that are. Scilab will in this case return %t if both inputs are equal. Program and documentation, unused, to the mathworks, inc. I want to compare each of those strings with a cell, and if the cell does not match any of the strings in the array, i. If used on an unsupported data type, strcmpi always returns 0.
3 1533 593 1517 1034 703 1562 831 1074 897 1430 1417 1103 563 648 179 751 394 1163 668 206 794 221 257 72 728 57 360 1239 1120 1049 882 244 1094 511