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Mixing integers and floating-point numbers in a basic arithmetic operation converts the integers automatically to floating point. In most cases, this gives exactly the desired results. But sometimes it matters precisely where the conversion occurs.

If `i`

and `j`

are integers, `(i + j) * 2.0`

adds them
as an integer, then converts the sum to floating point for the
multiplication. If the addition causes an overflow, that is not
equivalent to converting each integer to floating point and then
adding the two floating point numbers. You can get the latter result
by explicitly converting the integers, as in ```
((double) i +
(double) j) * 2.0
```

. See Explicit Type Conversion.

Adding or multiplying several values, including some integers and some
floating point, performs the operations left to right. Thus, ```
3.0 +
i + j
```

converts `i`

to floating point, then adds 3.0, then
converts `j`

to floating point and adds that. You can specify a
different order using parentheses: `3.0 + (i + j)`

adds `i`

and `j`

first and then adds that sum (converted to floating
point) to 3.0. In this respect, C differs from other languages, such
as Fortran.