var
Overview
The var
statement is used to create or update a variable which can subsequently be referenced by name in the USE script.
Syntax
[public] var
name [ = value]
[public] var
name operator number
[public] encrypt var
name = value
For details on encrypted variables please refer to the encrypt article
Details
Variables are created in one of two ways:
Manually via the
var
commandAutomatically, as a consequence of other statements in the script
If the word public
precedes a variable declaration then the variable will be shown in, and its value can be updated from, the Exivity GUI. Only variables prefixed with the word public
appear in the GUI (all others are only visible in the script itself). To make an automatic variable public, re-declare it with a value of itself as shown below:
Manually defined variables
A variable is a named value. Once defined, the name can be used in place of the value for the rest of the script. Amongst other things this permits configuration of various parameters at the top of a script, making configuration changes easier.
The = value portion of the statement is optional, but if used there must be white-space on each side of the =
character. To use spaces in a variable value it should be quoted with double quotes.
Once a variable has been defined it can be referenced by prefixing its name with ${
and post-fixing it with a }
. For example a variable called outputFile
can be referenced using ${outputFile}
. If no value is specified, then the variable will be empty, eg:
will result in the output:
Variable names are case sensitive, therefore ${variableName}
and ${VariableName}
are different variables.
If there is already a variable called name then the var
statement will update the value.
There is no limit to the number of variables that can be created, but any given variable may not have a value longer than 8095 characters
Arithmetic
Variables that contain a numeric value can have the arithmetic operations performed on them. This is done using the following syntax:
var
name operator number
The operator must be surrounded by white-space and following values are supported:
Operator | Meaning |
| Addition |
| Subtraction |
| Multiplication |
| Division |
For example the statement var x += 10
will add 10 to the value of x.
When performing arithmetic operations on a variable, any leading zeros in the value of that variable will be respected:
Attempting to perform an arithmetic operation on a variable that does not contain a valid number will result in an error being logged, and the script will terminate.
Currently, only integer arithmetic is supported.
Automatic variables
Automatic variables are referenced in exactly the same way as manually created ones; the only difference is in the manner of creation.
The following variables are automatically created during the execution of a USE script:
Variable | Details |
| The number of parameters passed to the script |
| For each parameter passed to the script a variable called |
| The day of the current local date, padded to 2 digits if necessary |
| The full English name of the current day of the week |
| The day of the current date in UTC, padded to 2 digits if necessary |
| The full English name of the current day o fthe week in UTC |
| The current local time in 'friendly' format, eg |
| A foreach loop creates this variable (where loop_name is the name of the loop). The value of the variable is updated every time the loop executes, with a value of |
| When iterating over the children of a JSON object (not an array) using foreach, these variables are updated with the name and value respectively of the current child every time the loop is executed (either may be blank if the child has no name or value respectively) |
| When iterating over the children of a JSON object (not an array) using foreach, this variable is updated to reflect the type of the current child every time the loop is executed. The type will be one of |
| The hour of the current local time, padded to 2 digits if necessary |
| The hour of the current time in UTC, padded to 2 digits if necessary |
| The HTTP status code returned by the server in response to the most recent http request executed. In case of transport-level failure contains value -1, HTTP_STATUS_TEXT variable contains error message |
| In case of transport-level failures, this variable will contain an error message intended to assist in identifying the issue |
| The minute of the current local time, padded to 2 digits if necessary |
| The minute of the current time in UTC, padded to 2 digits if necessary |
| The month of the current local date, padded to 2 digits if necessary |
| The full English name of the current month of the year |
| The month of the current date in UTC, padded to 2 digits if necessary |
| The full English name of the current month of the year in UTC |
| A newline ( |
| The second of the current local time, padded to 2 digits if necessary |
| The second of the current time in UTC, padded to 2 digits if necessary |
| The milliseconds of the current local time, padded to 3 digits if necessary |
| The milliseconds of the current time in UTC, padded to 3 digits if necessary |
| The filename of the script being executed |
| The current UTC time in YYYYMMDD'T'HHMMSS'Z' format, eg: |
| The year of the current local date as a 4 digit number |
| The year of the current date in UTC as a 4 digit number |
| Current UNIX time (seconds since 1 January 1970 00:00:00 UTC) |
To derive the short versions of the day and month names, use a match statement to extract the first 3 characters as follows:
match day "(...)" ${DAY_NAME_UTC}
var short_day = ${day.RESULT}
The .LENGTH suffix
On occasion it may be useful to determine the length (in characters) of the value of a variable. This can be done by appending the suffix .LENGTH
to the variable name when referencing it. For example if a variable called result has a value of success then ${result.LENGTH}
will be replaced with 7
(this being the number of characters in the word 'success').
A variable with no value will have a length of 0, therefore using the .LENGTH
suffix can also be used to check for empty variables as follows:
myvar.LENGTH
is not a variable in its own right. The .LENGTH
suffix merely modifies the manner in which the myvar
variable is used.
Examples
Basic variable creation and use
Creating encrypted variables
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