find index of an array which is matching value in num code example

Example 1: javascript get index of object with value in array

// Get index of object with specific value in array
const needle = 3;
const haystack = [{ id: 1 }, { id: 2 }, { id: 3 }];
const index = haystack.findIndex(item => item.id === needle);

Example 2: javascript indexof with condition

a = [
  {prop1:"abc",prop2:"qwe"},
  {prop1:"bnmb",prop2:"yutu"},
  {prop1:"zxvz",prop2:"qwrq"}
];
    
index = a.findIndex(x => x.prop2 ==="yutu");

console.log(index);

Example 3: numpy find index of matching values

import numpy as np
# init arrays
a = np.array([1,2,3,2,3,4,3,4,5,6])
b = np.array([7,2,10,2,7,4,9,4,9,8])

#using enumerate, list comprehension and set
print([key for key, val in enumerate(a) if val in set(b)])
# output
# [1, 3, 5, 7]