Lesson 13: Math)Today we will be discussing Math in JavaScript terms. The basis of any programming language can ultimately be broken down into a series of 1s and 0s. The patterns and flows created by these 1s and 0s are then manipulated in a language specific way using mathematics in some fashion. As webpage programmers (or application creators) we are not concerned with the underlying math that allows the browser's JavaScript interpreter to handle data, but rather how we can manipulate data of our choosing for use on top of the programming language as an application. 1) Arithmetic Operators + addition sum=1+1; sum==2 - subtration and/or negation diff=2-1; diff==2 * multiplication multi=2*3; mulit==6 / division div=4/2; div==2 % modulo (finds the remainder after division) mod=5%2; mod==1 ++ increment (add one) inc=0; inc++; inc==1 -- decrement (subtract one) dec=0; dec--; dec==(-1) () containers (JavaScript obeys algebraic rules) func1=1+2*3; func1==7 func2=(1+2)*3; func2==9 2) Math Constants Math.E is e, the base of the natural logarithm Math.LN10 is the natural logarithm of 10 Math.LN2 is the natural logarithm of 2 Math.LOG10E is the base-10 logarithm of e Math.LOG2E is the base-2 logarithm of e Math.PI is the circular constant of pi Math.SQRT1_2 is 1 divided by square root 2 Math.SQRT2 is the square root of 2 3) JavaScript Static Mathematic Functions Math.abs(x); absolute value of x Math.acos(x); inverse cosine of x (arc cosine) Math.asin(x); arc sine of x Math.atan2(x,y); computes angle from x axis Math.ceil(x); rounds x up to next integer Math.cos(x); the cosine of x Math.exp(x); set e to an the x power Math.floor(x); rounds down to previous integer Math.log(x); the natural logarithm of x Math.max(a,b); returns the larger of a or b Math.min(a,b); returns the smaller of a or b Math.pow(x,y); raises x to the y power Math.random(); a pseudo-random number between 0.0 and 1.0 Math.round(x); rounds x to nearst integer Math.sin(x); the sine of x Math.sqrt(x); the square root of x (NaN if<0) [Note- use powers to find other roots such as a cube root: cuberoot=Math.pow(27,1/3); cuberoot==3] Math.tan(x); the tangent of angle x |

Jerry aka WebWizard