I have an object method a like below:
var f = {
a: function(e){
e.call();
console.log(t); // Here should print “Hello world”
}
};
f.a(function(){
f.a.t = "Hello world";
// How to pass the string “Hello world” into the object method “a” ?
});
e is an anonymous function. I call the e and now I want to pass a string Hello world into the object method a. If it's not allowed to use global variable, how can I pass the string into the object method?
You may want to consider to change the return value of your eas below:
var f = {
a: function(e){
var t = e.call();//here declare variable t
console.log(t); // Here should print “Hello world”
}
};
f.a(function(){
return "Hello world";//directly return string value from anonymous function
// How to pass the string “Hello world” into the object method “a” ?
});
f and the anonymous function: you don't have to know the inner working of f in the anonymous function. In the other solutions -including the one I proposed- the anonymous function has to know that, in order to pass the string "Hello world", it has to set the value of the attribute t of object f or this (in which case, if you forget to add this to e.call(), it doesn't work).If you want to call e in the context of f then you would need to pass f to call, writing e.call() would be equal to e().
Beside that t refers to a variable and not to the property t of a. You cannot set a variable that way, but you could store it in the object f
You would write it that way.
var f = {
a: function(e){
e.call(this);
console.log(this.t);
}
};
f.a(function(){
this.t = "Hello world";
});
See below snippet
var f = {
a: function(e){
e.call();
console.log(f.a.t); // Here should print “Hello world”
}
};
f.a(function(){
f.a.t = "Hello world";
// How to pass the string “Hello world” into the object method “a” ?
});What is t's scope? If it's an attribute of f, write this:
var f = {
a: function(e){
e.call();
console.log(this.t); // this line changed
}
};
f.a(function(){
f.t = "Hello world"; // this line changed
});
Why not define a property in object like:
var f = {
t: '',
a: function(e){
e.call();
console.log(this.t); // Here should print “Hello world”
}
};
f.a(function(){
f.t = "Hello world";
});f is java script object and you can add property to that.I just added f.t="Hello world".you can use f.t anywhere in programme wherever you have f scope.
var f = {
a: function(e){
e.call();
console.log(f.t); // Here should print “Hello world”
}
};
f.a(function(){
f.t = "Hello world";
// How to pass the string “Hello world” into the object method “a” ?
});
