Evaluate MATLAB expression
eval( evaluates the
MATLAB® code in
Security Considerations: When calling
eval with untrusted user input, validate the input to avoid
unexpected code execution. Examples of untrusted user input are data coming from a user you
might not know or from a source you have no control over. If you need to address this
concern, consider these approaches:
Validate inputs to
eval. First, search for allowed
operations. Then, if you find other operations, disallow execution.
eval with an alternative. For more
information, see Alternatives to the eval Function.
Performance Considerations: In most cases, using the
eval function is also less efficient than using other
MATLAB functions and language constructs, and the resulting code can be more
difficult to read and debug. Consider using an alternative to
eval to evaluate and plot the
Z = eval('magic(5)'); mesh(Z)
expression— Expression to evaluate
Expression to evaluate, specified as a character vector or string scalar.
expression must be a valid MATLAB expression and must not include any MATLAB keywords. To determine whether a word is a MATLAB keyword, use the
output1,...,outputN— Outputs from evaluated expression
Outputs from evaluated expression, returned as any MATLAB data type.
If you use
eval within an anonymous function, nested
function, or function that contains a nested function, the evaluated
expression does not create any variables.
To allow the MATLAB parser to perform stricter checks on your code and avoid untrapped
errors and other unexpected behaviors, do not include output arguments in the
input to the
eval function. For example, the statement
eval(['output = ',expression]) is not recommended.
Instead, specify output arguments to the
eval function to
store the results of the evaluated expression. For example:
output = eval(expression)