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Format Into String Function

LabVIEW 2013 Help

Edition Date: June 2013

Part Number: 371361K-01

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Owning Palette: String Functions

Requires: Base Development System

Formats string, path, enumerated type, time stamp, Boolean, or numeric data as text.

Use the Format Into File function to format data as text and write the text to a file.


format string specifies how to convert the input arguments into resulting string. Defaults match the data type of the input arguments. Formatting a time stamp as anything other than time returns an error. Right-click the function and select Edit Format String from the shortcut menu to create and edit the format string. Use special escape codes to insert non-displayable characters, the backslash, and the percent characters.
initial string and any arguments appended to it form the resulting string.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
input 1..n specifies the input parameters to be converted. Each input can be a string, path, enumerated type, time stamp, or any numeric data type. You cannot use arrays and clusters with this function.
resulting string contains the concatenation of initial string and the formatted output.
error out contains error information. This output provides standard error out functionality.

Format Into String Details

Increase the number of parameters by right-clicking the function and selecting Add Parameter from the shortcut menu or by resizing the function.

Note  If an error occurs, source contains a string of the form Format Into String (arg n), where n is the first argument for which the error occurred.

If you wire a block diagram constant string to format string, LabVIEW uses format string to determine the number of outputs and the data type of each output at compile time. If the types you wire to the outputs do not match the types determined by format string, you must change the output types before the VI can run.

If you configure the Format Into String function to output exact strings, initial string is not required.

Specifying Which Input to Use within the Format String

By default, this function uses the order of the inputs to populate the format specifiers, or percent codes in the Format String. However, you can use a number followed by a dollar sign ($) within a percent code to specify exactly which input to use for that percent code. For example, the percent code %3$d uses the third input regardless of how many percent codes appear before it in the format string.

As a further example, refer to the following block diagram:

The following input combinations illustrate the effects of the $ specifier:

Input 1Input 2Format StringReturn StringComments
firstsecond%s %sfirst secondFormat String does not use the $ specifier, so the function populates the percent codes in input order.
firstsecond%2$s %1$ssecond firstFormat String uses the $ specifier to display the inputs in a different order than their input order.
firstsecond%1$s %1$s %1$sfirst first firstFormat String uses the $ specifier to display the first input multiple times and ignore the second input.

You can use other special characters besides the $ to configure how this function populates the percent codes in format string.


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