7.7: Comparing Text

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Page ID: 136672

Zara Noroozi
Irvine Valley College

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When comparing numbers, we often use operators such as ==. With text, it is usually better to use MATLAB text-comparison functions. These functions compare text character by character and return logical values: true or false.

Function	Purpose	Case sensitive?
strcmp(str1, str2)	Compares all characters in two pieces of text.	Yes
strncmp(str1, str2, n)	Compares only the first n characters.	Yes
strcmpi(str1, str2)	Compares all characters but ignores uppercase/lowercase differences.	No
strncmpi(str1, str2, n)	Compares the first n characters and ignores case.	No

Exercise \(\PageIndex{1}\)

Run the following commands and notice what MATLAB returns.


word1 = "cat";

word2 = "car";

word3 = "cathedral";

word4 = "CAR";



result_1 = strcmp(word1, word2)

result_2 = strcmp(word1, word3)

result_3 = strncmp(word1, word3, 3)

result_4 = strcmp(word2, word4)

result_5 = strcmpi(word2, word4)

The call strncmp(word1, word3, 3) returns true because the first three characters of "cat" and "cathedral" match. The call strcmp(word2, word4) returns false because one is lowercase and the other is uppercase. The function strcmpi ignores that case difference.

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