MATLAB: How to take a number as input

numeric inputoutputsimple input

I am, writing a code in which the user is aked to input a value. the value should be restricted to numbers only and no string. if the user enters anything other than a number error message should be displayed

Best Answer

You can create an input dialog box using answer = inputdlg(prompt,dlgtitle) (see that page for additional input options). The output will be a cell array of characters (or an empty cell array).

Convert the output to numeric

answerNum = str2double(answer);

Use a conditional error enforcing numeric input

if isempty(answerNum) || isnan(answerNum) % || ~isnumeric(answerNum)
    error('Input must be numeric.')
end

Related Solutions

MATLAB: Cell array of answers from user input

My choice would be inputdlg or one of its friends. It returns a cell array of strings of user input.

Example:

userinput = inputdlg({'A = ', 'B = '}, 'Input');

MATLAB: “if “function

You can use the isstrprop function. If answer is the input you got from your user (using the input command),

all(isstrprop(answer, 'digit'))

Here's an example:

while true
    answer = input('Enter a number: ', 's');
    if all(isstrprop(answer, 'digit'))
        answer = str2double(answer);
        break;
    else
        disp('Only numbers supported');
    end
end

Here's another way. This way is slightly better because it allows decimal points:

while true
    answer = input('Enter a number: ', 's');
    answer = str2double(answer);
    if ~isnan(answer)
        break;
    else
        disp('Only numbers supported');
    end
end

Best Answer

Related Solutions

MATLAB: Cell array of answers from user input

MATLAB: “if “function

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