parsefloat

问题 Is there a straightforward way to parse a string to either integer or float if I don't know if the variable is integer-number-like or decimal-number-like? a = '2'; // => parse to integer b = '2.1'; // => parse to float c = '2.0'; // => parse to float d = 'text'; // => don't parse EDIT: It seems my question lacked the necessary context: I want to do some calculations without losing the original format (Original format thereby means integer vs. float. I don't care about the original number of

问题 I've just started learning Go and I'm trying to convert a string from standard input to a float64 so I can perform an arithmetic operation on the input value. The output returns "0 feet converted to meters gives you 0 meters" regardless of the input value. I can't figure out why the value is zero after invoking ParseFloat on the input. If someone could please point out to me why this is happening, I would greatly appreciate it. const conversion float64 = 0.3048 func feetToMeters (feet float64

问题 I've just started learning Go and I'm trying to convert a string from standard input to a float64 so I can perform an arithmetic operation on the input value. The output returns "0 feet converted to meters gives you 0 meters" regardless of the input value. I can't figure out why the value is zero after invoking ParseFloat on the input. If someone could please point out to me why this is happening, I would greatly appreciate it. const conversion float64 = 0.3048 func feetToMeters (feet float64

问题 parseFloat(1.51e-6); // returns 0.00000151 parseFloat(1.23e-7); // returns 1.23e-7 // required 0.000000123 I am sorting table columns containing a wide range of floating-point numbers, some represented in scientific notation. I am using the jQuery tablesorter2.0 plugin which is using 'parseFloat' for cells that start with a digit. The issue is that parseFloat returns very small numbers represented as 1.23e-7 as a string and is not expanding this to 0.000000123. As a result tablesorter sorts

问题 Does parseFloat of a string have a limit to how many characters the string can be? I don't see anything about a limit here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseFloat But running the following in console seems to show results I wasn't expecting. parseFloat('1111111111111111'); // 16 characters long // result 1111111111111111 parseFloat('11111111111111111'); // 17 characters long // result 11111111111111112 Can anyone break this down for me? 回答1

问题 In this font-size resizing tutorial: Quick and easy font resizing the author uses parseFloat with a second argument, which I read here: parseFloat() w/two args Is supposed to specify the base of the supplied number-as-string, so that you can feed it '0x10' and have it recognized as HEX by putting 16 as the second argument. The thing is, no browser I've tested seems to do this. Are these guys getting confused with Java? 回答1: No, they're getting confused with parseInt() , which can take a radix

问题 Are there any side effects if i convert a string to a number like below.. var numb=str*1; If I check with the below code it says this is a number.. var str="123"; str=str*1; if(!isNaN(str)) { alert('Hello'); } Please let me know if there are any concerns in using this method.. 回答1: When you use parseFloat , or parseInt , the conversion is less strict. 1b5 -> 1. Using 1*number or +number to convert will result in NaN when the input is not valid number. Though unlike parseInt , floating point

问题 Hy guys, I have a case where a want to round the number to exactly two decimal places. I will give an example and what I tried. Lets say I have 15.07567 To round it up I did: price = Math.round(15.07567 * 100) / 100; // and I get 15.08 But this presents a problems if we have digits that end wit 0 (example 15.10) and we want two decimals. price = Math.round(15.10 * 100) / 100; //15.1 Hmmm, so I tried to use toFixed() price = Math.round(15.10 * 100) / 100; total = price.toFixed(2); // I get "15

问题 I'm trying to get parseFloat to convert a userInput ( prompt ) into a number. For example: var userInput = prompt("A number","5,000") function parse_float(number) { return parseFloat(number) } When userInput = 5,000 , parse_Float(userInput) returns 5 . However, if the user was inputting a value to change something else (ie: make a bank deposit or withdrawl) Then I to work properly, parse.Float(userInput) needs to return 5000 , not 5 . If anyone could tell me how to do this it would help me so

问题 I wrote a function that behaves differently depending on the numeric type of it's parameters. Integer or float. Using some code from this question How do I check that a number is float or integer? it was easy to detect if float or not but then I stumbled upon the case that javascript casts 1.0 to 1 without cause if you call a function using that number. Example: function dump(a, b) { console.log(a, typeof b, b); } dump('1', 1); dump('1.0', 1.0); dump('1.1', 1.1); Output chrome, firefox, ie,