Number-toXXX.md

• fixed-point 固定小数点
• Floating Point 浮動小数点
• exponential notation 指数表記

method	return
toFixed	f
toPrecision	f, e
toExponential	e

var int = 12345.67
;["toFixed", "toPrecision", "toExponential"].map(function(e){
  return  e + "|" +  [1,2,3,4,5,6,7,8].map(function(e2){
    return int[e](e2)
  }).join("|")
}).join("\n")

method/arg	1	2	3	4	5	6	7	8
toFixed	12345.7	12345.67	12345.670	12345.6700	12345.67000	12345.670000	12345.6700000	12345.67000000
toPrecision	1e+4	1.2e+4	1.23e+4	1.235e+4	12346	12345.7	12345.67	12345.670
toExponential	1.2e+4	1.23e+4	1.235e+4	1.2346e+4	1.23457e+4	1.234567e+4	1.2345670e+4	1.23456700e+4

method/arg	no-arg
toFixed	12346
toPrecision	12345.6789
toExponential	1.23456789e+4

toPrecision
引数が少 <------------> 多
  toExponential       toFixed