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# alert

var iMin = Math.min(3, 54, 32, 16);

alert(iMin); //outputs “3”

Out of the number 3, 54, 32, and 16,

max()

returns the number 54 whereas

min()

returns the number 3.

These methods are useful to avoid extra loops and

if

statements to determine the maximum value out

of a group of numbers.

Another method is

abs()

, which returns the absolute value of a number. The absolute value is the posi-

tive version of a negative number (positive numbers are their own absolute values).

var iNegOne = Math.abs(-1);

alert(iNegOne); //outputs “1”

var iPosOne = Math.abs(1);

alert(iPosOne); //outputs “1”

In this example,

abs(-1)

returns

1

and so does

abs(1)

.

The next group of methods has to do with rounding decimal values into integers. Three methods,

ceil()

,

floor()

, and

round()

, handle rounding in different ways.

?

The

ceil()

method represents the

ceiling

function, which always rounds numbers up to the

nearest value.

?

The

floor()

method represents the

floor

function, which always rounds numbers down to the

nearest value.

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The

round()

method represents a standard round function, which rounds up if the number is

more than halfway to the next value (0.5 of the way there) and rounds down if not. This is the

way you were taught to round in elementary school.

To illustrate how each of these methods works, consider using the value 25.5:

alert(Math.ceil(25.5)); //outputs “26”

alert(Math.round(25.5)); //outputs “26”

alert(Math.floor(25.5)); //outputs “25”

For

ceil()

and

round()

, passing in 25.5 returns 26, whereas

floor()

returns 25. Be careful not to use

these methods interchangeably because you could end up with some unexpected results.

Another group of methods relates to the use of exponents. These methods include the following:

exp()

,

which raises

Math.E

to a given power;

log()

, which returns the natural logarithm of a particular num-

ber;

pow()

, which raises a given number to a given power; and

sqrt()

, which returns the square root of

a given number.

Essentially,

exp()

and

log()

reverse each other, whereas

exp()

raises

Math.E

to a specific power and

log()

determines what exponent of

Math.E

is needed to equal the given value. For example:

var iNum = Math.log(Math.exp(10));

alert(iNum);

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