Initial Values of Variables

Every variable in a program must have a value before its value is used:

• Each array component is initialized with a default value when it is created. For type:

  • byte, the default value is zero, that is, the value of (byte)0.

  • short, the default value is zero, that is, the value of (short)0.

  • int, the default value is zero, that is, 0.

  • long, the default value is zero, that is, 0L.

  • BigInteger, the default value is zero, that is, 0IB.

  • float, the default value is positive zero, that is, 0.0f.

  • double, the default value is positive zero, that is, 0.0d.

  • BigDecimal, the default value is positive zero, that is, 0.0fb.

  • char, the default value is the null character, that is, '\u0000'.

  • Boolean, the default value is false.

  • String, the default value is the empty string, that is, "".

  • Prompt, the default value is the empty prompt, that is, P[].

  • Grammar, the default value is the empty grammar, that is, G[].

  • Document, the default value is the empty document, that is, DOC[].

  • Date, the default value is the current date at the time of interpretation.

  • Time, the default value is the current time at the time of interpretation.

  • Language, the default value is the system default language.

  • Currency, the default value is the system default currency.

  For all other reference types, the default value is null.

• Each complex block expression argument is initialized to the corresponding argument value provided by the invoker of the expression.

• An exception-handler parameter is initialized to the thrown object representing the exception and throw statements.

• A local variable and the for statement must be explicitly given a value before they are used, by either initialization or assignment, in a way that can be verified by the parser using the rules for definite assignment.