CODEWITHSUNDEEP
javascript
barrylachapelle
barrylachapelle

Reputation: 987

Changing the last digit of a float

I have a bunch of geojson data with may points being the exact same.

30.9694313

How would I isolate the last number and random increment it or decrement it landing on either 30.9694314 or 30.9694312?

I guess I could add or subtract 0.0000001, but how to handle this in the event of a dynamic float length?

Upvotes: 1

Views: 591

Answers (2)

barrylachapelle
barrylachapelle

Reputation: 987

Thanks for your help guys. This is what I came up with. I imagine there might be a cleaner way but this seems to work for me. Thanks for putting me on the right track.

noiselocation('-30.12345');

function noiselocation(coord){

    //num to string and strip special chars
    var coordstr = coord.toString();
    console.log('string: ' + coordstr);

    //get length
    var coordstrlength = coordstr.length-1;
    console.log('length: ' + coordstrlength);

    //get last char
    var coordlastchar = coordstr.charAt(coordstrlength);
    console.log('last char: ' + coordlastchar);

    //turn back to number
    coordlastnum = parseInt(coordlastchar);
    console.log('last num: ' + coordlastnum);

    //randomly increment up or down
    var randswitch  = Math.floor(Math.random() * 2) + 1;
    if(randswitch == "1"){
        coordlastnum++;
    }else{
        coordlastnum--;
    }
    console.log('last num after rand: ' + coordlastnum);

    //replace last char on string
    var newcoordstr = coordstr.slice(0, -1) + coordlastnum;
    console.log('new string: ' + newcoordstr);

    //turn string back to num
    newcoordnum = parseFloat(newcoordstr);
    console.log('new num: ' + newcoordstr);

}

Upvotes: 1

Barn on a Hill
Barn on a Hill

Reputation: 387

One way to do this would be to get a String representation of your float, and then parse the last digit as an integer. Then, you could increment/decrement it, add it back to the substring of your String to replace the old last digit, and parse it as a float. Not sure if this would be the most efficient way to do it, but it's the first thing to pop into my head.

Edit: some methods to help you (links to MDN)

Math.random()

Number.parseFloat(String)

Upvotes: 2

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