I got stuck with my code.
I wrote this sample code only for the purpose to reproduce my problem, so this code is not practical at all but I hope you get my point.
In the code below, for the last value to be output, I expect it to be 3, but it's undefined.
How am I supposed to write if I want the last value to be 3 in this case??
This is just a sample code, but in the actual code, I fetch content from amazon api and when it returns api error, I want to run the same function again after 1000 milli seconds.
var list = [1,2,3];
var someClass = new SomeClass();
list.forEach(function(value) {
var result = someClass.getSomething(value);
console.log("outside: " + result);
});
function SomeClass() {
var flag = false;
this.getSomething = function(something) {
if (something === 3 && flag === false) {
flag = true;
this.getSomething(something);
//I need to return here, so the succeeding code is not read.
return;
}
console.log("inside: " + String(something));
return something;
}
}
Log
inside: 1
outside: 1
inside: 2
outside: 2
inside: 3
outside: undefined // I expect this value to be 3!!!
You have a test:
if (something === 3 && flag === false) { //... return;
If you want to return 3
then don't have a return
statement with nothing after it. return
means return undefined
. Put return 3
or return something
.
You probably want to return from your recursive call though:
return this.getSomething(something);
Here's the problem:
function SomeClass() {
var flag = false;
this.getSomething = function(something) {
if (something === 3 && flag === false) {
flag = true;
this.getSomething(something); // not returning this
return; // returning undefined
}
console.log("inside: " + String(something));
return something;
}
}
Here's the fix:
function SomeClass() {
var flag = false;
this.getSomething = function(something) {
if (something === 3 && flag === false) {
flag = true;
return this.getSomething(something);
}
console.log("inside: " + String(something));
return something;
}
}
change the code to
if (something === 3 && flag === false) {
flag = true;
return this.getSomething(something);
}
"return;" returns undefined
It returns undefined
in your code because you return;
in the if
clause.
return this.getSomething(something)
within the if
clause
var list = [1, 2, 3];
var someClass = new SomeClass();
list.forEach(function(value) {
var result = someClass.getSomething(value);
console.log("outside: " + result);
});
function SomeClass() {
var flag = false;
this.getSomething = function(something) {
if (something === 3 && flag === false) {
flag = true;
return this.getSomething(something);
}
console.log("inside: " + String(something));
return something;
}
}
forEach loop doesn't return a value. You can create a global variable and assign values to it.
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