Not an expert on the old JS so here goes
I have
store1.baseParams.competition = null;
store2.baseParams.competition = null;
store3.baseParams.competition = null;
What I want to do is
for (i=1; 1<=3; 1++) {
store + i +.baseParams.competition = null;
}
Hope that makes sense what I want to do - is it possible
Basically make a variable / object by adding to it
Cheers
One way to accomplish this is via eval() - (usually a Very Bad Idea)
for (var i=1; i<=3; i++) {
eval("store" + i + ".baseParams.competition = null;");
}
Another, more complex but relatively efficient way would be to create a function which gives you the ability to mutate arbitrarily deep object hierarchies dynamically at run-time. Here's one such function:
/*
Usage:
Nested objects:
nested_object_setter(object, ['property', 'propertyOfPreviousProperty'], someValue);
Top-level objects:
nested_object_setter(object, 'property', someValue);
*/
function dynamic_property_setter_base(obj, property, value, strict) {
var shouldPerformMutation = !strict || (strict && obj.hasOwnProperty(property));
if(shouldPerformMutation) {
obj[property] = value;
}
return value;
}
function dynamic_property_setter(obj, property, value) {
return dynamic_property_setter_base(obj, property, value, false);
}
function nested_object_setter(obj, keys, value) {
var isArray = function(o) {
return Object.prototype.toString.call(o) === '[object Array]';
};
//Support nested keys.
if(isArray(keys)) {
if(keys.length === 1) {
return nested_object_setter(obj, keys[0], value);
}
var o = obj[keys[0]];
for(var i = 1, j = keys.length - 1; i < j; i++)
o = o[keys[i]];
return dynamic_property_setter(o, keys[keys.length - 1], value);
}
if(keys != null &&
Object.prototype.toString.call(keys) === '[object String]' &&
keys.length > 0) {
return dynamic_property_setter(obj, keys, value);
}
return null;
}
Your code would look like this:
for(var i = 1; i <= 3; i++)
nested_object_setter(this, ['store' + i, 'baseParams', 'competition'], null);
Here's another example, running in the JS console:
> var x = {'y': {'a1': 'b'}};
> var i = 1;
> nested_object_setter(this, ['x','y','a' + i], "this is \"a\"");
> x.y.a1
"this is "a""
Another way to do it, IMHO this is the simplest but least extensible way:
this['store' + i].baseParams.competition = null;
var x = {'y': {'a': 'b'}}; x.y.a = 'this is \'a\''; is sufficient here.
That won't work. You can make an object though, storing the 'store'+i as a property.
var storage = {},i=0;
while(++i<4) {
storage['store' + i] = { baseParams: { competition:null } };
}
Console.log(String(storage.store1.baseParams.competition)); //=> 'null'
In a browser, you can also use the window namespace to declare your variables (avoiding the use of eval):
var i=0;
while(++i<4) {
window['store' + i] = { baseParams: { competition:null } };
}
Console.log(String(store1.baseParams.competition)); //=> 'null'
for (i=1; i<=3; i++) {
this["store" + i + ".baseParams.competition"] = null;
}
Just another form of assigning variables in JS.
