Open Watcom FORTRAN 77 Language Reference

Language Reference
8.6 Extended Assignment Statement
Open Watcom FORTRAN 77 supports an extension to the FORTRAN 77 assignment statement, namely
the extended assignment statement.
v = v = v = ... = v = e
1 2 3 n
where:
v’i
must be one of the following:
1. Variable names or array element names of type INTEGER, REAL, DOUBLE
PRECISION, COMPLEX or double precision complex (COMPLEX*16).
2. Variable names or array element names of type LOGICAL.
3. Character variable names, character array elements, or character substrings.
e
must be one of the following and must follow the rules of the arithmetic, logical or character
assignment statements:
1. An arithmetic expression.
2. A logical expression.
3. A character expression.
The extended assignment statement is equivalent to the following individual statements.
v = e
n
v = v
n-1 n
.
.
.
v = v
2 3
v = v
1 2
When using an extended assignment statement involving variables of mixed type, it is important to
understand the exact way in which the assignments are performed. Assignment of each variable is made
using the value of the variable to its immediate right, starting with the rightmost variable which is assigned
the value of the expression. To help make this clear, consider the following program.
190 Extended Assignment Statement