Choose Command Syntax or Function Syntax
MATLAB has two ways of calling functions, called function syntax and command syntax. This page
discusses the differences between these syntax formats and how to avoid common mistakes
associated with command syntax.
For introductory information on calling functions, see “Calling Functions”. For information related to
defining functions, see “Create Functions in Files” on page 20-2.
Command Syntax and Function Syntax
In MATLAB, these statements are equivalent:
load durer.mat
% Command syntax
load('durer.mat')
% Function syntax
This equivalence is sometimes referred to as command-function duality.
All functions support this standard function syntax:
[output1, ..., outputM] = functionName(input1, ..., inputN)
In function syntax, inputs can be data, variables, and even MATLAB expressions. If an input is data,
such as the numeric value 2 or the string array ["a" "b" "c"], MATLAB passes it to the function
as-is. If an input is a variable MATLAB will pass the value assigned to it. If an input is an expression,
like 2+2 or sin(2*pi), MATLAB evaluates it first, and passes the result to the function. If the
functions has outputs, you can assign them to variables as shown in the example syntax above.
Command syntax is simpler but more limited. To use it, separate inputs with spaces rather than
commas, and do not enclose them in parentheses.
functionName input1 ... inputN
With command syntax, MATLAB passes all inputs as character vectors (that is, as if they were
enclosed in single quotation marks) and does not assign outputs to variables. To pass a data type
other than a character vector, use the function syntax. To pass a value that contains a space, you have
two options. One is to use function syntax. The other is to put single quotes around the value.
Otherwise, MATLAB treats the space as splitting your value into multiple inputs.
If a value is assigned to a variable, you must use function syntax to pass the value to the function.
Command syntax always passes inputs as character vectors and cannot pass variable values. For
example, create a variable and call the disp function with function syntax to pass the value of the
variable:
A = 123;
disp(A)
This code returns the expected result,
123
You cannot use command syntax to pass the value of A, because this call
disp A
is equivalent to
Choose Command Syntax or Function Syntax
1-7
MATLAB has two ways of calling functions, called function syntax and command syntax. This page
discusses the differences between these syntax formats and how to avoid common mistakes
associated with command syntax.
For introductory information on calling functions, see “Calling Functions”. For information related to
defining functions, see “Create Functions in Files” on page 20-2.
Command Syntax and Function Syntax
In MATLAB, these statements are equivalent:
load durer.mat
% Command syntax
load('durer.mat')
% Function syntax
This equivalence is sometimes referred to as command-function duality.
All functions support this standard function syntax:
[output1, ..., outputM] = functionName(input1, ..., inputN)
In function syntax, inputs can be data, variables, and even MATLAB expressions. If an input is data,
such as the numeric value 2 or the string array ["a" "b" "c"], MATLAB passes it to the function
as-is. If an input is a variable MATLAB will pass the value assigned to it. If an input is an expression,
like 2+2 or sin(2*pi), MATLAB evaluates it first, and passes the result to the function. If the
functions has outputs, you can assign them to variables as shown in the example syntax above.
Command syntax is simpler but more limited. To use it, separate inputs with spaces rather than
commas, and do not enclose them in parentheses.
functionName input1 ... inputN
With command syntax, MATLAB passes all inputs as character vectors (that is, as if they were
enclosed in single quotation marks) and does not assign outputs to variables. To pass a data type
other than a character vector, use the function syntax. To pass a value that contains a space, you have
two options. One is to use function syntax. The other is to put single quotes around the value.
Otherwise, MATLAB treats the space as splitting your value into multiple inputs.
If a value is assigned to a variable, you must use function syntax to pass the value to the function.
Command syntax always passes inputs as character vectors and cannot pass variable values. For
example, create a variable and call the disp function with function syntax to pass the value of the
variable:
A = 123;
disp(A)
This code returns the expected result,
123
You cannot use command syntax to pass the value of A, because this call
disp A
is equivalent to
Choose Command Syntax or Function Syntax
1-7