Get Index of Array Containing Value from Multi-dimensional Array in JS

Question

Suppose I have a multi dimensional array in JavaScript:

var arr = [
 ['cat','23','5123'],
 ['dog','53','522'],
 ['bird','335','512'],
 ['horse','853','152'], 
 ['monkey','13','5452']
];

And I want to get the index of the array in arr that contains horse in the first index (output should be 3).

I can do this in the following way:

var index_i_need;
for(var i in arr){
 if(arr[i][0]==='horse') {
 index_i_need = i;
 break;
 }
}
console.log(index_i_need); // 3
console.log(arr[index_i_need]); // ['horse','853','152']

But this isnt scaleable.

Id like to have some more direct method like indexOf(), for instance.

I know findIndex() takes a callback function but I havent been able to apply it correctly.

Any suggestions?

• Redu: arr.findIndex(sa => sa[0] === "horse");

Answer 1

You can use a dynamic find function, findByAnimal, to use in findIndex

function findByAnimal(animal) {
 return function(innerArr){
 return innerArr[0] === animal
 }
}
arr.findIndex( findByAnimal('horse') )

The way findIndex works is each item in arr is passed into the callback, the first "truthy" return value from callback will yield the index, or -1 if no items return truthy.

• julian soro: Thanks @James, I quickly realized the same and updated the answer
• julian soro: @yevg if you found this useful, feel free to mark as answered or provide feedback. thanks