input

Request user input

Description

example

x = input(prompt) displays the text in prompt and waits for the user to input a value and press the Return key. The user can enter expressions, like pi/4 or rand(3), and can use variables in the workspace.

• If the user presses the Return key without entering anything, then input returns an empty matrix.

• If the user enters an invalid expression at the prompt, then MATLAB® displays the relevant error message, and then redisplays the prompt.

example

str = input(prompt,'s') returns the entered text, without evaluating the input as an expression.

Examples

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Request a numeric input, and then multiply the input by 10.

prompt = 'What is the original value? ';
x = input(prompt)
y = x*10

At the prompt, enter a numeric value or array, such as 42.

x =
42

y =
420

The input function also accepts expressions. For example, rerun the code.

prompt = 'What is the original value? ';
x = input(prompt)
y = x*10

At the prompt, enter magic(3).

x =
8     1     6
3     5     7
4     9     2

y =
80    10    60
30    50    70
40    90    20

Request a simple text response that requires no evaluation.

prompt = 'Do you want more? Y/N [Y]: ';
str = input(prompt,'s');
if isempty(str)
str = 'Y';
end

The input function returns the text exactly as typed. If the input is empty, this code assigns a default value, 'Y', to str.

Input Arguments

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Text displayed to the user, specified as a character vector.

To create a prompt that spans several lines, use '\n' to indicate each new line. To include a backslash ('\') in the prompt, use '\\'.

Output Arguments

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Result calculated from input, returned as an array. The type and dimensions of the array depend upon the response to the prompt.

Exact text of the input, returned as a character vector.

Algorithms

The Workspace browser does not refresh while input is waiting for a response from the user. Therefore, if you run input within a script, the Workspace browser does not display changes made to variables in the workspace until the script finishes running.