simulation of balls falling into normal distribution to teach javascript

galton.js

function rand(max) {
  return parseInt(Math.random() * max);
}

function f(h, i) {
    if (rand(1000) < 500) {
        return i
    }
    return i + 1
}

function zerofill (list) {
    i = 0
    n = list.length
    while (i < n) {
        list[i++] = 0    
    }
}

function simulation(balls, depth) {
    result_list = Array(depth)
    zerofill(result_list)
    
    b = 0
    while (b < balls) {
        h=0
        i=0
        while (h < depth) {
            i = f(h, i)
            h=1+h      
        }
        result_list[i] = result_list[i] + 1
        b++
    }

    logArray(result_list)
}

function log(s) {
    console.log(s)
}

function logArray(l) {
   i = -1    
   while (++i < l.length) {
        log("i = "+ i + " = " + l[i])
   }     
}

function testZeroFill() {
   l =  Array(100)
   x = zerofill(l)
   log("x is ... " + x)
   
}

//testZeroFill()

balls = 9000000
depth = 20
simulation(balls, depth)