更換零（整數）與空間（字符串）與JavaScript

Question

我計算年齡從出生日期，但是當我返回值是顯示「0」爲更多參見下面的代碼

var birth = new Date('DOB'); 
var curr = new Date(); 
var age; // this is integer type in database 
if(birth != null) 
{ 
    var diff = curr - birth; 
    age= Math.floor(diff/(1000 * 60 * 60 * 24 * 365.25)); 
} else { 
    age=' '; // while i return space from here it shows '0' on my output 
} 

我該怎麼讓空間insted的'0'

Answer 1

將其替換爲'null'至null。它不是字符串。

var curr = new Date(); 
var age; // this is integer type in database 
    if(R2 != null && R2 != undefined) 
    { 
     var diff = curr - birth; 
    AGE= Math.floor(diff/(1000 * 60 * 60 * 24 * 365.25)); 
}else 
AGE=' '; // while i return space from here it shows '0' on my output 
} 

Answer 2

我對代碼做了很少的修改，因爲我不能修改它的結構。主要的變化是檢查age是零還是小於零，因爲如果出生日期在過去一年或將來，原始代碼確實返回0或甚至負數。這應該工作。

var birth = new Date('DOB'); 
var curr = new Date(); 
var age; // this is integer type in database 
if (birth != null) 
{ 
    var diff = curr - birth; 
    age = Math.floor(diff/(1000 * 60 * 60 * 24 * 365.25)); 
    if (age < 1) { 
     age = ' '; 
    } 
} else { 
    age = ' '; // while i return space from here it shows '0' on my output 
}