Replace the Nan values with 0 in Java

Question

Hello i need to replace the Nan values with 0 in my array in java, any help thanks. you can find the example of my array.

The array type is double and the contents of array are as follows.

x = [ 1 , 2, Nan , 4, Nan ]

@forrestg There is a static variable [Double.NaN](https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#NaN) — seenukarthi, Mar 31 '21 at 10:56
DoubleStream.of(values).map(operand -> Double.isNaN(operand) ? 0d : operand).mapToObj(String::valueOf).collect(Collectors.toList()); double[] doubles = DoubleStream.of(values).map(operand -> Double.isNaN(operand) ? 0d : operand).toArray(); System.out.println(Arrays.toString(doubles)); — silentsudo, Apr 02 '21 at 13:15

score 6 · Accepted Answer · answered Mar 31 '21 at 10:54

6

Loop the array and use isNaN method from Double to check if the number is NaN.

for(int i=0; i<array.length; i++){
    if(Double.isNaN(array[i])) {
        array[i] = 0d;
    }
}

answered Mar 31 '21 at 10:54

Gautham M

4,816
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score 2 · Answer 2 · answered Mar 31 '21 at 10:58

2

In Java Nan != Nan evaluates to true.

double[] x = { 1 , 2, Double.NaN , 4, Double.NaN};
System.out.println(Arrays.toString(x));
for (int i = 0; i < x.length; i++) {
    if(x[i]!=x[i]) {
        x[i] = 0;
    }
}
System.out.println(Arrays.toString(x));

Output:

[1.0, 2.0, NaN, 4.0, NaN]
[1.0, 2.0, 0.0, 4.0, 0.0]

answered Mar 31 '21 at 10:58

the Hutt

16,980
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Nice trick, but I'll stick with `Double.isNaN` since the equality may change in future version of java. – seenukarthi Mar 31 '21 at 11:16
This is literally how `isNaN` is implemented in my jdk: `return (v != v)` – Marty Neal Oct 04 '22 at 07:31

Replace the Nan values with 0 in Java

2 Answers2