using string in if statement

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Oyewale Oyelami
Oyewale Oyelami el 18 de Jul. de 2011
Respondida: NgoiKH el 29 de Oct. de 2021
i want to use string in my if boolean expression....something like if(name =='daniel') disp...... All i have been getting are errors...is it possible and if yes how? Thanks

Respuestas (3)

Walter Roberson
Walter Roberson el 18 de Jul. de 2011
If you attempt to compare two strings using == and the strings are not the same length, then you will get errors. == can be used for strings only if they are the same length.
Use strcmp() or isequal() or strcmpi().
  2 comentarios
N/A
N/A el 26 de Mzo. de 2019
What if I'm using an if statement where I want the if condition to be met if the string being compared has only a part of the actual string
How do I make that work?
example
button = buttons
if button ==contains(str, "butt")
run()
else
stop()
end
Steven Lord
Steven Lord el 26 de Mzo. de 2019
Working with a string array is different than working with a char array. What Walter wrote is true for char arrays (which was the main data type for storing text data in 2011, as the string class didn't exist yet.)
button = "button";
str = 'abcde';
if contains(str, button)
disp("[" + str + "] contains the string [" + button + "]")
else
disp("[" + str + "] doesn't contain the string [" + button + "]")
end
Now change the contents of the str variable and perform the same comparison.
str = 'space button';
if contains(str, button)
disp("[" + str + "] contains the string [" + button + "]")
else
disp("[" + str + "] doesn't contain the string [" + button + "]")
end
The contains function can accept two char vectors, two string arrays, two cell arrays containing char vectors, or a combination of those three types.

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Fangjun Jiang
Fangjun Jiang el 18 de Jul. de 2011
The following code should work. You can also use isequal(MyName,'Daniel'), strcmp(), strcmpi() etc.
MyName='Daniel';
if MyName=='Daniel'
disp('correct name');
else
disp('wrong name')
end
  2 comentarios
Jan
Jan el 18 de Jul. de 2011
But this will *not* work: "MyName = 'Daniela'; if MyName == 'Daniel', ...", because the arrays compared by == must have the same size or one is a scalar.
Fangjun Jiang
Fangjun Jiang el 18 de Jul. de 2011
Now I understand why the OP had errors. I personally never use == to compare strings. The error message should be pretty clear though, right?

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NgoiKH
NgoiKH el 29 de Oct. de 2021
str = 'abc'
if strcmp('abc',str)
expression
else
expression
end

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