How to find a object name by closest range value?

Question

my try:

var objects = [
  {"min":"0","max":"50","name":"name1"},
  {"min":"50","max":"100","name":"name2"},
  {"min":"100","max":"150","name":"name3"}
];

var value = 40;

objects.forEach(function(item, i){
    if(Number(item.min) >= value &&  value <= Number(item.max) ){
    console.log("name is ", item.name );
  }
});

getting console as :

name is  name2
name is  name3

but my expectation is name is name2 what is the correct way to get the range value with scenario?

value = 40, lies between 0 to 50, console should print `name1`? — Sajal, Oct 06 '17 at 12:33
you're checking if 50 >= 40 && 40<= 100 ... something's wrong here ! — Mathieu VIALES, Oct 06 '17 at 12:33
Possible duplicate of [Does JavaScript have a method like "range()" to generate an array based on supplied bounds?](https://stackoverflow.com/questions/3895478/does-javascript-have-a-method-like-range-to-generate-an-array-based-on-suppl) — Liam, Oct 06 '17 at 12:34
what is the result with `value = 500`? what means closest range in this case? or is it just insufficient wording? — Nina Scholz, Oct 06 '17 at 13:19

Joe Keene · Answer 1 · 2017-10-06T12:44:31.157

2

Move the value variable so that you're checking if it is greater or equal to the min, otherwise you're checking if the min is greater than or equal to value:-

let objects = [
    {"min":"0","max":"50","name":"name1"},
    {"min":"50","max":"100","name":"name2"},
    {"min":"100","max":"150","name":"name3"}
];

let value = 40;

objects.forEach(function(item, i){
    if (value >= Number(item.min) && value <= Number(item.max)) {
        console.log("name is ", item.name );
    }
});

edited Oct 06 '17 at 12:44

answered Oct 06 '17 at 12:33

Joe Keene

2,175
21
27

if I change value to 50, it gives 2 out puts. – 3gwebtrain Oct 06 '17 at 12:39
yes it will...as you have `>=` and `<=` if you don't want the number included then remove the `=` so you only have greater than and less than. – Joe Keene Oct 06 '17 at 12:40

score 2 · Answer 2 · answered Oct 06 '17 at 12:36

Use Array#find method:

var objects = [
  {"min":"0","max":"50","name":"name1"},
  {"min":"50","max":"100","name":"name2"},
  {"min":"100","max":"150","name":"name3"}
];

var value = 90;

let res = objects.find(obj => Number(obj.min) <= value && value <= Number(obj.max));
console.log(res ? res.name : 'Not found');

score 1 · Answer 3 · answered Oct 06 '17 at 12:35

Here we go, you just had to swap variables:

if(Number(item.min) >= value &&  value <= Number(item.max) ){

if(value >= Number(item.min) &&  value <= Number(item.max) ){

var objects = [
  {"min":"0","max":"50","name":"name1"},
  {"min":"50","max":"100","name":"name2"},
  {"min":"100","max":"150","name":"name3"}
];

var value = 40;

objects.forEach(function(item, i){
    if(value >= Number(item.min) &&  value <= Number(item.max) ){
    console.log("name is ", item.name );
  }
});

llama · Answer 4 · 2017-10-06T12:59:26.633

If your ranges increment by 50, you don't need to iterate at all. We just divide value by 50 and rounded down, giving us the index.

const index = n && Math.floor(n/50) - !(n%50);

Any range from x1 to x50 will be in the lower range, so values like 150 are handled. The 0 value is included in the first range.

var objects = [
  {"min":"0","max":"50","name":"name1"},
  {"min":"50","max":"100","name":"name2"},
  {"min":"100","max":"150","name":"name3"}
];

test(0);
test(10);
test(50);
test(51);
test(100);
test(149);
test(150);
test(151);

function test(n) {
  const index = n && Math.floor(n/50) - !(n%50);
  const res = objects[index];
  console.log("value:", n, ", item:", res ? res.name : 'Not found');
}

@3gwebtrain: I added a new example that deals with numbers that land on a multiple of 50. — llama, Oct 06 '17 at 12:48

How to find a object name by closest range value?

4 Answers4