如何通过值（如果包含）获取键在数组中的索引？

Question

Here's my what I meant.

var brands = [['brand: LV'], ['brand: Apple']]...

With this, I want to position(index) of say..Apple. Manually, I can easily do

brands[1]

But this gets dynamically updated, therefor the index will be random.

Answer 1

Use findIndex() or indexOf() .

Example : brands.findIndex(doc => doc[0] === 'brand: Apple') .

Answer 2

Your format is a little inconvenient, normally you would have an array of objects not an array of strings like this, but at any rate you can still:

 let brands = [ ['brand: LV'],['brand: Apple']] let f = brands.findIndex(subarray => subarray.some(i => i.includes('Apple'))) console.log(f, brands[f]) 

Note that since you have these arrays it accounts for the possibility of one of them having more than one value. So consider:

 let brands = [['brand: LV'], ['brand: Sony', 'brand: Apple']] let f = brands.findIndex(subarray => subarray.some(i => i.includes('Apple'))) console.log(f, brands[f]) 

If you know each subarray will only have one value, you can just test for that:

 let brands = [ ['brand: LV'],['brand: Apple']] let f = brands.findIndex(subarray => subarray[0].includes('Apple')) console.log(f, brands[f]) 

Answer 3

Since your data is an array of arrays, a simple includes or indexOf won't work on the top level, you need to test each element. Using findIndex allows you to apply a custom function to each element in turn:

 let brands = [ ['brand: LV'], ['brand: Apple'] ]; function findBrand(name) { let testValue = `brand: ${name}`; return brands.findIndex( elem => elem.includes(testValue) ); } console.log(findBrand('Apple'))