I have an array that looks like this:
[{
name: 'foobar',
fields: [{
label: 'argle'
},{
label: 'bargle'
}]
},{
name: 'baz',
fields: [{
label: 'rar'
},{
label: 'hoogah'
}]
}]
I'm looking for the index of the object which has a field matching label === 'rar', so I can update that particular field. Is there an optimum way to accomplish this? I know indexOf won't get me there by itself, but I'm struggling with the logic.
You can use the findIndex and some methods of Array.
[
{name: 'foobar', fields: [{label: 'argle'}, {label: 'bargle'}]},
{name: 'baz', fields: [{label: 'rar'}, {label: 'hoogah'}]}
].findIndex(function(element, index, array) {
return element.fields.some(function(element, index, array) {
return element.label === 'rar';
});
})
returns 1
With arrow functions you can do the searches shown in Mathieu's answer nice and cleanly
let arr = [
{name: 'foobar', fields: [{label: 'argle'}, {label: 'bargle'}]},
{name: 'baz', fields: [{label: 'rar'}, {label: 'hoogah'}]}
];
Then
arr.findIndex(item => item.fields.some(deepItem => deepItem.label === 'rar')); // 1
If you're more interested in accessing the item itself, not it's index, then use arr.find instead
arr.find(item => item.fields.some(deepItem => deepItem.label === 'rar')); // Object
Further, if you want every item which matches, then use arr.fileter instead
arr.filter(item => item.fields.some(deepItem => deepItem.label === 'rar')); // [{...}, ...]
a 'normal' way of doing it:
var arr = [
{name: 'foobar', fields: [{label: 'argle'}, {label: 'bargle'}]},
{name: 'baz', fields: [{label: 'rar'}, {label: 'hoogah'}]},
{name: 'foo', fields: [{label: 'asjda'}, {label: 'hoogah'}]}
];
function findByLabel(arr, str) {
var res = null;
arr.forEach(function(item) {
if (item.fields[0].label == 'rar')
res = item
});
return res;
}
console.log(findByLabel(arr, 'rar'));
an ugly way of doing it.
var data = [
{name: 'foobar', fields: [{label: 'argle'}, {label: 'bargle'}]},
{name: 'baz', fields: [{label: 'rar'}, {label: 'hoogah'}]}
],
i = data.findIndex(e => ~e.fields.findIndex(f => f.label == 'rar'));
// returns 1
