CIF 3

RealsΒΆ

Reals or real numbers are numbers with a fractional part. Examples include 1.56 and -2.7e6 (scientific notation for 2.7 million). Real numbers must either have a fraction or use the scientific notation, to distinguish them from integer numbers. The default value of reals (real type) is 0.0. Several standard arithmetic operators and functions are available to work with reals:

+1.23           // 1.23
--1.2           // 1.2

1.5 + 0.5       // 2.0
1.5 - 0.5       // 1.0
1.5 * 0.5       // 0.75
1.5 / 0.5       // 3.0

pow(3.5, 2.0)   // 7.0      (3.5 to to the power of 2, or 3.5 * 3.5)
abs(-1.5)       // 1.5      (absolute value)
min(1.5, 0.5)   // 0.5      (minimum value)
max(1.5, 0.5)   // 1.5      (maximum value)

sqrt(16.0)      // 4.0      (square root)
cbrt(16.0)      // 2.0      (cube root)

sin(1.0)        // 0.841... (sine)
cos(1.0)        // 0.540... (cosine)
tan(1.0)        // 1.557... (tangent)

log(100.0)      // 2.0      (logarithm to base 10)
ln(100.0)       // 4.605... (natural logarithm)

Real values can be compared to other real values, as well as to integer values:

x < y       // less than
x <= y      // less than or equal to
x = y       // equal to
x != y      // not equal to
x >= y      // larger than or equal to
x > y       // larger than

Integer numbers can often be written where real numbers are expected. Real values and integer values can also often be combined using arithmetic operators and functions. Furthermore, it is possible to convert between them:

sqrt(16)    // 4.0 (16 interpreted as 16.0)
1 + 0.5     // 1.5 (addition of an integer number and a real number)
max(0.5, 1) // 1.0 (maximum of an integer number and a real number)

<real>1     // 1.0 (cast from integer to real, explicit conversion)
round(1.6)  // 2   (round real to closest integer, half up)
ceil(0.7)   // 1   (round real up to integer)
floor(0.7)  // 0   (round real down to integer)

This lesson does not show all details regarding reals, nor does it show all available operations and functions. For further details, see the language reference manual.