I am trying to remove an object from an array if a particular value for a key matches a given string:
Example data:
array = [{_id: "abc", test: "123"},
{_id: "def", test: "123"},
{_id: "ghi", test: "123"}];
Here is my loop:
for (var i = 0; i < array.length; i++) {
var x = "123"
if (array[i].test == x) {
array.splice(i, 1)
}
}
This should return an empty array but it's leaving one object in the array (the last one) and I've got no clue why.
You must not increment i if you remove an element.
Suppose the array has two matching elements.
The first iteration, i = 0
i ==>> element 1
element 2
You then remove element 1, and increment i
element 2
i ==>>
There are many ways you can correct this. Here's an example that replaces your for loop with a while loop.
var i = 0;
while (i < array.length) {
var x = "123"
if (array[i].test == x) {
array.splice(i, 1)
} else {
++i;
}
}
array = [
{id: "abc", test: "123"},
{id: "def", test: "456"},
{id: "ghi", test: "789"}
];
let x = "123";
let i = array.findIndex(data => data.test === x);
if (i !== -1) {
array.splice(i, 1);
} else ...
console.log(array);
Figured it out:
array = array.filter(function(array) {
var x = "123";
return array.test !== x;
})
I have written a function that takes the index and event values from the html and processes in ts
app.component.html
<tr *ngFor="let container of containers; let i = index;"
[(ngModel)]="miningname"
ngDefaultControl>
<td>
<input *ngIf="addMore" type="text" class = "form-control"
placeholder="Key"
[(ngModel)]="container.key2Name"
(ngModelChange)="textKeyChangedMore($event,i)">
</td></tr>
app.component.ts
textKeyChangedMore(eventMore, indexMore) {
var valueLength = this.selectedAPIName.length
var i = indexMore+1;
if (this.selectedAPIName[i].value == undefined ) {
this.selectedAPIName.splice(indexMore + 1, 1, { key: eventMore, value: undefined });
}
else if (this.selectedAPIName[i].value !== undefined) {
this.selectedAPIName.splice(indexMore + 1, 1, { key: eventMore, value: this.selectedAPIName[i].value });
}
}
for ( var i = array.length; i--; ). That works because when you remove an element only the indices of elements past that one are affected; elements before it are not touched, so if you are iterating backwards, removing an element won't affect the index of future elements in your loop.