programming-for-dummies

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Manipulating Strings
Most likely, you won’t have any idea, but you don’t have to because you can
calculate the square root of a number just by using that language’s built-in
square root math function. So if you wanted to know the square root of 34
and store it in an Answer variable, you could just use the sqrt math function,
such as
Answer = sqrt(34)
In some languages, such as BASIC, it doesn’t matter if you type a math
function in either uppercase or lowercase. In other languages, such as C,
commands like SQRT and sqrt are considered two completely different
functions, so you must know if your language requires you to type a math
function in all uppercase or all lowercase.
Table 3-4 lists some common built-in math functions found in many programming
languages.
Table 3-4
Common Built-In Math Functions
Math Function What It Does Example
abs (x) Finds the absolute value of x abs (–45) = 45
cos (x) Finds the cosine of x cos (2) = – 0.41614684
exp (x) Returns a number raised to the power of x exp (3) = 20.0855369
log (x) Finds the logarithm of x log (4) = 1.38629436
sqrt (x) Finds the square root of x sqrt (5) = 2.23606798
By using math operators and math functions, you can create complex equations,
such as
x = 67 * cos (5) + sqrt (7)
Rather than plug fixed values into a math function, it’s more flexible just to
plug in variables instead, such as
Angle = 5
Height = 7
X = 67 * cos (Angle) + sqrt (Height)
Manipulating Strings
Just as math operators can manipulate numbers, so can string operators
manipulate strings. The simplest and most common string operator is the
concatenation operator, which smashes two strings together to make a single
string.