Details

This message is generated by an attempted assignment to part of the value of a symbol when the symbol does not have an immediate value.
It is necessary to initialize the value of a symbol before making assignments to parts of the value of that symbol.
Immediate values can be assigned using Set (lhs=rhs). Delayed values can be assigned using SetDelayed (lhs:=rhs).
Off[message] switches off the message; On[message] switches it on. For example: Off[General::noval].

Examples

If the symbol vector does not have a value, this assignment to vector[[1]] will generate an error, and the assignment will not be made:

A similar error will occur if the value of vector is a delayed value:

The assignment works as intended if vector has an immediate value:

Clear the value of vector:

Top