I have the following array, of which I'm trying to perform a search for a particular element:
grid ({"row": row, "col": col})
Can anyone provide advice on how to locate an element in this array? I've tried something like this, but I can't seem to figure out if I'm doing it correctly.
grid.indexOf([row, col])
Any advice would be great.
This isn't an array, it's an object.
For an array you could just use:
array.forEach(function(element, index, array) {});
Since this is an object however you need to do a little more work:
Object.keys(grid).forEach(function(element, index, array) {
if(element === some_random_name) {
// Do whatever you need to here.
}
});
[[Prototype]] chain, so you might match an inherited property rather than an own property. Object.keys avoids that. It may not be required for an ad hoc solution, but it is for a general case.Inside of your array you are keeping objects, so comparing them only by value does not work in JS.
You can do it the old fasion way (iterate):
function indexOfCell(row, col){
for(var i=0; i< grid.length;i++){
if(grid[i].row === row && grid[i].col === col){ // this code can get complex, when working with many properties
return i;
}
}
return -1;
}
Second solution would be filter from Array prototype:
function filterByRowAndCol(element) {
if (element.row === row && element.col === col) {
return element;
} else {
invalidEntries++;
}
}
var arrByRowAndCol = grid.filter(filterByID);
Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
This is an object, to access the element in your object you can use like this
grid = {"row": 10, "col": 12 };
alert( grid.row ); //will alert 10
alert( grid.col ); //will alert 12
You're working with an object, not an array.
You'll also need to refine your syntax for the object to work with it correctly. Try this: var grid = {'row': 'row', 'col': 'col'};
Then, you can loop through your object properties to find what you need:
var findValue = function (someKey) {
for (var property in grid) {
if (grid.hasOwnProperty(property)) {
if (property === someKey) {
return grid.property // return the value
}
}
}
};
