Format data into string or character vector (2024)

str = sprintf(formatSpec,A1,...,An)

[str,errmsg]= sprintf(formatSpec,A1,...,An)

str = sprintf(literalText)

str = sprintf(formatSpec,A1,...,An) formats the data in arrays A1,...,An using the formatting operators specified by formatSpec and returns the resulting text in str. The sprintf function formats the values in A1,...,An in column order. If formatSpec is a string, then so is the output str. Otherwise, str is a character vector.

To return multiple pieces of formatted text as a string array or a cell array of character vectors, use the compose function.

• The formatSpec parameter must be constant.

• In formatSpec, hexadecimal numbers must be in the range [0 7F] and octal numbers must be in the range [0 177].

• If all the input arrays are constant, the code generator evaluates the sprintf call in MATLAB at compile time. In this case, the code generation restrictions for sprintf do not apply and the behavior of sprintf in the generated code is the same as the behavior in MATLAB.

• If extrinsic calls are not possible, the code generator produces C code for sprintf. Extrinsic calls are not possible when extrinsic calls are disabled or when sprintf is called inside a parfor loop.

• The behavior of sprintf in the generated code matches the C compiler behavior instead of the MATLAB behavior in these cases:

  • The format specifier has a corresponding C format specifier, for example, %e or %E.

  • The sprintf call is inside a parfor loop.

  • Extrinsic calls are disabled.

• These options and capabilities are not supported:

  • The n$ position identifier for reordering input values

  • Printing arrays

  • Using subtypes to print a floating-point number as its octal, decimal, or hexadecimal value

• When you call sprintf with the format specifier %s, you cannot put a null character in the middle of the input character vector. To write a null character, use sprintf(fid, '%c', char(0)).

• Input argument types must match their format types. For example, if n is a double, code generation does not allow the following code:

  str = sprintf('%d',n)

  For code generation, first cast n to a signed integer type such as int8.

  str = sprintf('%d',int8(n))

• When you call sprintf with an integer format specifier, the type of the integer argument must be a type that the target hardware can represent as a native C type. For example, if you call sprintf('%d', int64(n)), then the target hardware must have a native C type that supports a 64-bit integer.

• Dynamic memory allocation must be enabled.