查找数组中最近的浮点数

Question

How would I get the nearest float in my array to a float of my choice? Here is my array:

[1.20, 1.50, 1.75, 1.95, 2.10]

For example, if my float was 1.60 , I would like to produce the float 1.50 .

Any ideas? Thanks in advance!

Answer 1

You can do it by sorting the array and finding the nearest one.

For this you can use sortDescriptors and then your algorithm will go.

Even you can loop through, by assuming first as the required value and store the minimum absolute ( abs() ) difference, if next difference is lesser than hold that value.

The working sample, however you need to handle other conditions like two similar values or your value is just between two value like 2 lies between 1 and 3.

NSArray *array = @[@1.20, @1.50, @1.75, @1.95, @2.10];

double my = 1.7;
NSNumber *nearest = array[0];

double diff = fabs(my - [array[0] doubleValue]);
for (NSNumber *num in array) {
    double d = [num doubleValue];
    if (diff > fabs(my - d) ) {
        nearest = num;
        diff = my - d;
    }
}

NSLog(@"%@", nearest);