JavaScript：显示带加号的正数
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JavaScript: Display positive numbers with the plus sign
提问by Soso
How would I display positive number such as 3 as +3 and negative numbers such -5 as -5? So, as follows:
我如何将正数（例如 3）显示为 +3，将负数（例如 -5）显示为 -5？所以，如下：
1, 2, 3 goes into +1, +2, +3
1, 2, 3 进入 +1, +2, +3
but if those are
但如果这些是
-1, -2, -3 then goes into -1, -2, -3
-1, -2, -3 然后进入 -1, -2, -3
回答by Guffa
You can use a simple expression like this:
您可以使用这样的简单表达式：
(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.
如果数字是正数，条件表达式会产生一个加号，如果数字是负数，则结果为空字符串。
You haven't specified how to handle zero, so I assumed that it would be displayed as +0. If you want to display it as just 0, use the <=operator instead:
您还没有指定如何处理零，所以我假设它会显示为+0. 如果您想将其显示为 just 0，请改用<=运算符：
(n<=0?"":"+") + n
回答by Tom Gullen
// Forces signing on a number, returned as a string
function getNumber(theNumber)
{
if(theNumber > 0){
return "+" + theNumber;
}else{
return theNumber.toString();
}
}
This will do it for you.
这将为您做到。
回答by 01001111
printableNumber = function(n) { return (n > 0) ? "+" + n : n; };
回答by hvgotcodes
write a js function to do it for you?
写一个 js 函数来为你做这件事？
something like
就像是
var presentInteger = function(toPresent) {
if (toPresent > 0) return "+" + toPresent;
else return "" + toPresent;
}
you could also use the conditional operator:
您还可以使用条件运算符：
var stringed = (toPresent > 0) ? "+" + toPresent : "" + toPresent;
Thanx to the comments for pointing out that "-" + toPresent would put a double -- on the string....
感谢评论指出“-”+ toPresent 会在字符串上放一个双--...
回答by Samuel
function format(n) {
return (n>0?'+':'') + n;
}
回答by Alex Murphy
['','+'][+(num > 0)] + num
or
或者
['','+'][Number(num > 0)] + num
It is a shorter form than the ternary operator, based on casting boolean to the number 0 or 1 and using it as an index of an array with prefixes, for a number greater than 0 the prefix '+' is used
它是比三元运算符更短的形式，基于将布尔值转换为数字 0 或 1 并将其用作具有前缀的数组的索引，对于大于 0 的数字，使用前缀“+”
回答by neiker
Modern syntax solution.
现代语法解决方案。
It also includes a space between sign and number:
它还包括符号和数字之间的空格：
function getNumberWithSign(input) {
if (input === 0) {
return "0"
}
const sign = input < 0 ? '-' : '+';
return `${sign} ${Math.abs(input)}`;
}
回答by Mark Mayo
something along the lines of:
类似的东西：
if (num > 0)
{
numa = "+" + num;
}
else
{
numa = num.toString();
}
and then print the string numa.
然后打印字符串numa。
