CODEWITHSUNDEEP
javascriptarraysconcatenation
Jaffer Abyan Syed
Jaffer Abyan Syed

Reputation: 129

trying to pull an array value from a list of numbers but value comes back invalid array length

I am trying to a pull array item number from a specific array.

for example if the input value has a number between 2.59 and 2.79 like 2.65

the output using this function 

   const gpaToLevel = [].concat(...
        [1.99, 2.19, 2.39, 2.59, 2.79, 2.99, 3.19, 3.39, 3.59, 3.79, 4.00].map((ending, j, endValue) =>
            Array(ending - (endValue[j-1] || -1)).fill(j)
        )
    );

should be 4, because 2.65 is less than 2.79 and 2.79 has a value of [4].

thank you

Upvotes: 2

Views: 79

Answers (1)

Mark
Mark

Reputation: 92440

I think what you are looking for is findIndex(). It takes a callback and will return the index of the first item where the callback returns true.

So if your array is sorted you can use:

arr = [1.99, 2.19, 2.39, 2.59, 2.79, 2.99, 3.19, 3.39, 3.59, 3.79, 4.00]

// 4
console.log(arr.findIndex(item => item > 2.65))
// 5 
console.log(arr.findIndex(item => item > 2.85))
// 0
console.log(arr.findIndex(item => item > 1.85))

// -1 -- no items greater than 4.0
console.log(arr.findIndex(item => item > 4.5))

Upvotes: 2

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