仅当数字小于两位小数时才添加.00(toFixed)

Question

我需要添加零,以便每个数字至少有两位小数,但没有舍入.例如:

5      --> 5.00
5.1    --> 5.10
5.11   --> 5.11 (no change)
5.111  --> 5.111 (no change)
5.1111 -->  5.1111  (no change) 

我的函数缺少一个IF来检查少于两个小数位:

function addZeroes( num ) {
   var num = Number(num);
   if ( //idk ) {
      num = num.toFixed(2);
   }
   return num;
}

谢谢!

除了以下两个之外,还会发布一个替代答案.(请记住,我不是专家,这只是用于文本输入,而不是用于解析复杂值,例如可能存在浮点问题的颜色等)

function addZeroes( value ) {
    //set everything to at least two decimals; removs 3+ zero decimasl, keep non-zero decimals
    var new_value = value*1; //removes trailing zeros
    new_value = new_value+''; //casts it to string

    pos = new_value.indexOf('.');
    if (pos==-1) new_value = new_value + '.00';
    else {
        var integer = new_value.substring(0,pos);
        var decimals = new_value.substring(pos+1);
        while(decimals.length<2) decimals=decimals+'0';
        new_value = integer+'.'+decimals;
    }
    return new_value;
}

[这不是一个重复的问题.您链接的问题假设"知道他们至少有1个小数." 在文本输入中不能假设小数点,这就是错误.]

Answer 1

干得好:

function addZeroes(num) {
// Convert input string to a number and store as a variable.
    var value = Number(num);      
// Split the input string into two arrays containing integers/decimals
    var res = num.split(".");     
// If there is no decimal point or only one decimal place found.
    if(res.length == 1 || res[1].length < 3) { 
// Set the number to two decimal places
        value = value.toFixed(2);
    }
// Return updated or original number.
return value;
}

// If you require the number as a string simply cast back as so
var num = String(value);

请参阅更新的小提琴进行演示.

http://jsfiddle.net/jhKuk/159/

Answer 2

以下代码提供了一种方法来执行您想要的操作.还有其他人.

function addZeroes( num ) {
   // Cast as number
   var num = Number(num);
   // If not a number, return 0
   if (isNaN) {
        return 0;
   }
   // If there is no decimal, or the decimal is less than 2 digits, toFixed
   if (String(num).split(".").length < 2 || String(num).split(".")[1].length<=2 ){
       num = num.toFixed(2);
   }
   // Return the number
   return num;
}

http://jsfiddle.net/nzK4n/

alert(addZeroes(5)); // Alerts 5.00
alert(addZeroes(5.1)); // Alerts 5.10
alert(addZeroes(5.11)); // Alerts 5.11
alert(addZeroes(5.111)); // Alerts 5.111

Answer 3

也许使用.toLocaleString()：

var num = 5.1;    
var numWithZeroes = num.toLocaleString("en",{useGrouping: false,minimumFractionDigits: 2});
console.log(numWithZeroes);

作为功​​能/演示：

var num = 5.1;    
var numWithZeroes = num.toLocaleString("en",{useGrouping: false,minimumFractionDigits: 2});
console.log(numWithZeroes);

而且，如果您必须使用.toFixed()，那么这里是单线：

var num = 5.1;    
var numWithZeroes = num.toFixed(Math.max(((num+'').split(".")[1]||"").length, 2));
console.log(numWithZeroes);

或者，再次作为功能/演示：

function addZeroes(num) {
   return num.toLocaleString("en", {useGrouping: false, minimumFractionDigits: 2})
}

console.log('before   after       correct');
console.log('5      ->', addZeroes(5) , '  --> 5.00');
console.log('5.1    ->', addZeroes(5.1) , '  --> 5.10');
console.log('5.11   ->', addZeroes(5.11) , '  --> 5.11 (no change)');
console.log('5.111  ->', addZeroes(5.111) , ' --> 5.111 (no change)');
console.log('5.1111 ->', addZeroes(5.1111) , '--> 5.1111 (no change)');
console.log('-5     ->', addZeroes(-5) , ' --> -5.00');

Answer 4

decimalNumber = number => Number.isInteger(number) ? number.toFixed(2) : number