Definition: In most modern programming languages which are strongly typed, the compiler will not allow the use of a variable or function unless that function or variable has already been declared.
This lets the compiler check parameters or variable type and report type mismatches or undeclared variables.
Glossary:
A B C D E F G H I J K L M N O P Q R S T U V W X Y ZExamples:
I forgot to declare the variable and the compiler found three errors.
