OpenEuphoria: Euphoria v4.1

# OpenEuphoria Manual

## Euphoria v4.1

routine or constant name search

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## 4.3 Assignment statement

An assignment statement assigns the value of an expression to a simple variable, or to a subscript or slice of a variable. e.g.

    x = a + b
    y[i] = y[i] + 1
    y[i..j] = {1, 2, 3}

The previous value of the variable, or element(s) of the subscripted or sliced variable are discarded. For example, suppose x was a 1000-element sequence that we had initialized with:

    object x

    x = repeat(0, 1000)  -- a sequence of 1000 zeros

and then later we assigned an atom to x with:

    x = 7

This is perfectly legal since x is declared as an object. The previous value of x, namely the 1000-element sequence, would simply disappear. Actually, the space consumed by the 1000-element sequence will be automatically recycled due to Euphoria's dynamic storage allocation.

Note that the equals symbol '=' is used for both assignment and for equality testing. There is never any confusion because an assignment in Euphoria is a statement only, it can't be used as an expression (as in C).

### 4.3.1 Assignment with Operator

Euphoria also provides some additional forms of the assignment statement.

To save typing, and to make your code a bit neater, you can combine assignment with one of the operators:

    + - / * &

For example, instead of saying:

    mylongvarname = mylongvarname + 1

You can say:

    mylongvarname += 1

Instead of saying:

    galaxy[q_row][q_col][q_size] = galaxy[q_row][q_col][q_size] * 10

You can say:

    galaxy[q_row][q_col][q_size] *= 10

and instead of saying:

    accounts[start..finish] = accounts[start..finish] / 10

You can say:

    accounts[start..finish] /= 10

In general, whenever you have an assignment of the form:

    left-hand-side = left-hand-side op expression

You can say:

    left-hand-side op= expression

where op is one of:

    + - * / &

When the left-hand-side contains multiple subscripts/slices, the `op=` form will usually execute faster than the longer form. When you get used to it, you may find the `op=` form to be slightly more readable than the long form, since you don't have to visually compare the left-hand-side against the copy of itself on the right side.

You cannot use assignment with operators while declaring a variable, because that variable is not initialized when you perform the assignment.

| Up |  |  | TOC | Index
<< 3 Using Euphoria | < 4.2 Declarations | Up: 4 Language Reference | 4.4 Branching Statements > | 5 Formal Syntax >>