So you want to get the second digit from the decimal writing of a number. The simplest and most logical solution is to convert it to a string : var digit = (”+myVar)[1]; or var digit = myVar.toString()[1]; If you don’t want to do it the easy way, or if you want a more efficient … Read more
You can use a simple expression like this: (n<0?””:”+”) + n The conditional expression results in a plus sign if the number is positive, and an empty string if the number is negative. You haven’t specified how to handle zero, so I assumed that it would be displayed as +0. If you want to display … Read more
1e5 is a number expressed using scientific notation, specifically E notation, and it means 1 multiplied by 10 to the 5th power (the ‘e’ meaning ‘exponent’). So 1e5 equals 1*100000 and is equal to 100000. The three notations are interchangeable meaning the same.
What’s a Number? I have a simple question for your “simple” question: What precisely do you mean by “a number”? Is −0 a number? How do you feel about √−1? Is ⅝ or ⅔ a number? Is 186,282.42±0.02 miles/second one number — or is it two or three of them? Is 6.02e23 a number? Is … Read more
The integer cases are easy. The double case is trickier, until you remember about infinities. Note: If you consider the double constants “part of the api”, you can replace them with overflowing expressions like 1E308 * 2. int sign(int i) { if (i == 0) return 0; if (i >> 31 != 0) return -1; … Read more
As of Swift 2, all integer types have a constructor init?(_ text: String, radix: Int = default) so that both integer to hex string and hex string to integer conversions can be done with built-in methods. Example: let num = 1000 let str = String(num, radix: 16) print(str) // “3e8” if let num2 = Int(str, … Read more
In JSON, 6 is the number six. “6” is a string containing the digit 6. So the answer to the question “Can json numbers be quoted?” is basically “no,” because if you put them in quotes, they’re not numbers anymore. But, should the parsers accept both “attr” : 6 and “attr” : “6”? Yes, but … Read more
function decimalPlaces(num) { var match = (”+num).match(/(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/); if (!match) { return 0; } return Math.max( 0, // Number of digits right of decimal point. (match[1] ? match[1].length : 0) // Adjust for scientific notation. – (match[2] ? +match[2] : 0)); } The extra complexity is to handle scientific notation so decimalPlaces(‘.05’) 2 decimalPlaces(‘.5’) 1 decimalPlaces(‘1’) … Read more
Try max($var,0), which will have the desired effect. See the manual page for more information.