for (var i = 0; i < somearray.length; i++)
{
myclass.foo({'arg1':somearray[i][0]}, function()
{
console.log(somearray[i][0]);
});
}
How do I pass somearray or one of its indexes into the anonymous function ? somearray is already in the global scope, but I still get somearray[i] is undefined
The i in the anonymous function captures the variable i, not its value. By the end of the loop, i is equal to somearray.length, so when you invoke the function it tries to access an non-existing element array.
You can fix this by making a function-constructing function that captures the variable's value:
function makeFunc(j) { return function() { console.log(somearray[j][0]); } }
for (var i = 0; i < somearray.length; i++)
{
myclass.foo({'arg1':somearray[i][0]}, makeFunc(i));
}
makeFunc's argument could have been named i, but I called it j to show that it's a different variable than the one used in the loop.
How about a closure:
for (var i = 0; i < somearray.length; i++) {
var val = somearray[i][0];
myclass.foo({'arg1': val}, function(v) {
return function() {console.log(v) };
}(val) );
}
for (var i = 0; i < somearray.length; i++)
{
myclass.foo({'arg1':somearray[i][0]}, function(somearray)
{
console.log(somearray[i][0]);
});
}
And then in method foo call anonymous function with param.
You can pass variables values to annoymous function by using callback, something like
myclass.foo(function(variable){
return function(){
console.log(variable);
}
})(variableValue);
);
check this post: https://shahpritesh.wordpress.com/2013/09/06/javascript-function-in-loop-passing-dynamic-variable-value/
All the functions/methods can be used as callbacks only. When you call the callback function you pass variables to it.
var myclass = {
foo: function(params, callback){
// do some stuff
callback(variable1, variable1, variableN);
}
}
