# 10 ASSIGNMENT STATEMENTS

Completion of execution of an assignment statement causes definition of an entity.

There are four kinds of assignment statements:

1. Arithmetic
2. Logical
3. Statement label (ASSIGN)
4. Character

## 10.1 Arithmetic Assignment Statement

The form of an arithmetic assignment statement is:

```      v = e
```

where:

• v is the name of a variable or array element of type integer, real, double precision, or complex
• e is an arithmetic expression

Execution of an arithmetic assignment statement causes the evaluation of the expression e by the rules in Section 6, conversion of e to the type of v, and definition and assignment of v with the resulting value, as established by the rules in Table 4.

#### Table 4 Arithmetic Conversion and Assignment of e to v

```                        _______________________________
|                  |          |
| Type of v        | Value    |
|                  | Assigned |
|__________________|__________|
|                  |          |
| Integer          | INT(e)   |
|__________________|__________|
|                  |          |
| Real             | REAL(e)  |
|__________________|__________|
|                  |          |
| Double precision | DBLE(e)  |
|__________________|__________|
|                  |          |
| Complex          | CMPLX(e) |
|__________________|__________|
```

The functions in the "Value Assigned" column of Table 4 are generic functions described in Table 5 (15.10).

## 10.2 Logical Assignment Statement

The form of a logical assignment statement is:

```      v = e
```

where:

• v is the name of a logical variable or logical array element
• e is a logical expression

Execution of a logical assignment statement causes the evaluation of the logical expression e and the assignment and definition of v with the value of e. Note that e must have a value of either true or false.

## 10.3 Statement Label Assignment (ASSIGN) Statement

The form of a statement label assignment statement is:

```      ASSIGN s TO i
```

where:

• s is a statement label
• i is an integer variable name

Execution of an ASSIGN statement causes the statement label s to be assigned to the integer variable i. The statement label must be the label of a statement that appears in the same program unit as the ASSIGN statement. The statement label must be the label of an executable statement or a FORMAT statement.

Execution of a statement label assignment statement is the only way that a variable may be defined with a statement label value.

A variable must be defined with a statement label value when referenced in an assigned GO TO statement (11.3) or as a format identifier (12.4) in an input/output statement. While defined with a statement label value, the variable must not be referenced in any other way.

An integer variable defined with a statement label value may be redefined with the same or a different statement label value or an integer value.

## 10.4 Character Assignment Statement

The form of a character assignment statement is:

```      v = e
```

where:

• v is the name of a character variable, character array element, or character substring
• e is a character expression

Execution of a character assignment statement causes the evaluation of the expression e and the assignment and definition of v with the value of e. None of the character positions being defined in v may be referenced in e. v and e may have different lengths. If the length of v is greater than the length of e, the effect is as though e were extended to the right with blank characters until it is the same length as v and then assigned. If the length of v is less than the length of e, the effect is as though e were truncated from the right until it is the same length as v and then assigned.

Only as much of the value of e must be defined as is needed to define v. In the example:

```      CHARACTER A*2,B*4
A=B
```

the assignment A=B requires that the substring B(1:2) be defined. It does not require that the substring B(3:4) be defined.

If v is a substring, e is assigned only to the substring. The definition status of substrings not specified by v is unchanged.

This document was translated by troff2html v0.21 on August 16, 1995.