In ModelBuilder, contents of a variable can be used as a substitute for another variable by enclosing the substituting variable in percent signs (%). Substituting variables in this manner is called inline variable substitution. A simple case of inline variable substitution is replacing some text or a value in a model with user input.
For examples of inline variable substitution, see the following:
Inline variable classification
Inline variables are classified into two types:
- Model variables—Any variable in a model: %variable name%.
- System variable—There are two system variables in ModelBuilder: %i% for a list number of a variable and %n% as the iteration number in the model.
Rules for using inline variables
- Enclose the variable name in percent signs (%).
- Spaces within the variable name are allowed.
- Substitution is not case sensitive. Initial Value and initial value are equivalent.
Search order for inline variables
When a model executes, the inline variables are identified and used in the following order:
- Model variables.
- Model environment settings.
- System variables (%i% and %n%).
- Variables in the parent model. If the currently running model is a submodel, the parent model's variables are searched.