Showing Two minimum values in javascript

Milan
July 28, 2024
182 views
3 votes
3 Answers

Here is a sample of an array where i want to find the minimum from the .value in the array but when i try to do this which for loop it first give me the real minimum value but after it override with another value which not the minimum but the second last minimum
`

const AlzheimerData = [
    {
        "location": "world",
        "year": "2000",
        "value": "9.557819"
    },
    {
        "location": "world",
        "year": "2001",
        "value": "10.267346"
    },
    {
        "location": "world",
        "year": "2002",
        "value": "10.8148"
    },
    {
        "location": "world",
        "year": "2003",
        "value": "11.329527"
    }
]

var alzehemersmin = Number.MAX_VALUE;

for( data of AlzheimerData){
    if(data.value < alzehemersmin){
        alzehemersmin = data.value;
    }
    console.log(alzehemersmin);
}

output in console :

9.557819  --- Alzheimer.js:156:13 -- the real minimum value
10.267346 --- Alzheimer.js:156:13 -- the overided minimum value

I am expecting to get only the real minimum value which is the first one

Answers

Using the Math function may be an alternative;

const AlzheimerData = [
    {
        "location": "world",
        "year": "2000",
        "value": "9.557819"
    },
    {
        "location": "world",
        "year": "2001",
        "value": "10.267346"
    },
    {
        "location": "world",
        "year": "2002",
        "value": "10.8148"
    },
    {
        "location": "world",
        "year": "2003",
        "value": "11.329527"
    }
]

function findMin(key) {
  const datas = AlzheimerData.map((node) => node[key]);
  return Math.min(...datas)
}
console.log(findMin('value'));

- VusalHuseynov
- July 28, 2024 at 9:21 am
- 0 votes
0
It’s because you are comparing strings not floats. First, convert data.value to float and then compare them to find minimum.
```
const AlzheimerData = [...]

var alzehemersmin = Number.MAX_VALUE;

for( data of AlzheimerData){
    const value = Number.parseFloat(data.value)
    alzehemersmin = Math.min(value,alzehemersmin)
}

console.log(alzehemersmin);
```
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This can be done in a one-liner:

const alzheimerData = [
    {
        "location": "world",
        "year": "2000",
        "value": "9.557819"
    },
    {
        "location": "world",
        "year": "2001",
        "value": "10.267346"
    },
    {
        "location": "world",
        "year": "2002",
        "value": "10.8148"
    },
    {
        "location": "world",
        "year": "2003",
        "value": "11.329527"
    }
];

const minValue = Math.min(...Object.values(alzheimerData).map(({value}) => parseFloat(value)));

document.write(`The minimum value is: ${minValue}`);