I'd like to convert this code:
for (var i = 0; i < product.ages.length; i ++){
for (var j = 0; j < $scope.ages.length; j ++){
if (product.ages[i].id == $scope.ages[j].id){
$scope.ages[j]['ticked'] = true;
}
}
}
into underscore.js. please help.
Another way to solve this problem would be to first create a hash of the scope.ages using underscore's indexBy:
var scope_ages = _.indexBy($scope.ages, 'id');
The object would look something like:
{
1: ref to scope.ages with id 1,
2: ref to scope.ages with id 2,
etc.
}
Then iterate over the product ages using each to set the ticked value:
_.each(product.ages, age => scope_ages[age.id].ticked = true)
var product = {
ages: [
{ id : 1 }
]
}
var $scope = {
ages: [
{ id : 0, ticked: false },
{ id : 1, ticked: false },
{ id : 2, ticked: false },
]
}
var scope_ages = _.indexBy($scope.ages, 'id');
_.each(product.ages, age => scope_ages[age.id].ticked = true)
document.getElementById('scope_ages').textContent = JSON.stringify(scope_ages);
document.getElementById('result').textContent = JSON.stringify($scope.ages);<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore.js"></script>
<h1>scope_ages</h1>
<p>
<pre id="scope_ages"></pre>
</p>
<h1>Scope</h1>
<p>
<pre id="result"></pre>
</p>This would be your code in underscore:
_.each(product.ages, function(pAge) {
_.each($scope.ages, function(sAge) {
if (pAge.id === sAge.id) {
sAge.ticked = true;
}
});
});
Here is an example on how you do an _.each on an object.
var example = {"hello":"world", "this":"is", "super":"neat"};
_.each(example, function(value, index){
console.log(index + ":" + value);
}
->hello:world
->this:is
->super:neatYou can use _.find
_.each($scope.ages, function(v){
v.ticked = _.find(product.ages, function(a){
return v.age === a.age;
})?true:false;
})
Also, just a pointer, you should use break on match.
