why is my callback function not updating my var in React
0
How can I access "string value" outside the scope of the callback function. Please forgive my primitive knowledge as i'm new to callbacks.
render() {
let test = '';
let callback = (string) => {
test = string
console.log <----returns "string value"
}
console.log(test) <-----returns empty string
console.log()
return (
<div>
{callback("string value")}
</div>
);
}
}
javascript reactjs ecmascript-6
asked Nov 24 '18 at 22:44
RayRay
347
add a comment |
0
How can I access "string value" outside the scope of the callback function. Please forgive my primitive knowledge as i'm new to callbacks.
render() {
let test = '';
let callback = (string) => {
test = string
console.log <----returns "string value"
}
console.log(test) <-----returns empty string
console.log()
return (
<div>
{callback("string value")}
</div>
);
}
}
javascript reactjs ecmascript-6
asked Nov 24 '18 at 22:44
RayRay
347
1
Because when youconsole.log(test), thecallbackfunction has not yet been called (it happens later in thereturnstatement).
– Bergi
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value oftestis still the empty string. I'm not sure what is the point though, what are you trying to do?
– Stefan
Nov 24 '18 at 22:50
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51
add a comment |
0
0
0
How can I access "string value" outside the scope of the callback function. Please forgive my primitive knowledge as i'm new to callbacks.
render() {
let test = '';
let callback = (string) => {
test = string
console.log <----returns "string value"
}
console.log(test) <-----returns empty string
console.log()
return (
<div>
{callback("string value")}
</div>
);
}
}
javascript reactjs ecmascript-6
asked Nov 24 '18 at 22:44
RayRay
347
How can I access "string value" outside the scope of the callback function. Please forgive my primitive knowledge as i'm new to callbacks.
render() {
let test = '';
let callback = (string) => {
test = string
console.log <----returns "string value"
}
console.log(test) <-----returns empty string
console.log()
return (
<div>
{callback("string value")}
</div>
);
}
}
javascript reactjs ecmascript-6
javascript reactjs ecmascript-6
asked Nov 24 '18 at 22:44
RayRay
347
asked Nov 24 '18 at 22:44
RayRay
347
asked Nov 24 '18 at 22:44
RayRay
347
asked Nov 24 '18 at 22:44
RayRay
347
asked Nov 24 '18 at 22:44
RayRay
347
347
1
Because when youconsole.log(test), thecallbackfunction has not yet been called (it happens later in thereturnstatement).
– Bergi
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value oftestis still the empty string. I'm not sure what is the point though, what are you trying to do?
– Stefan
Nov 24 '18 at 22:50
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51
add a comment |
1
Because when youconsole.log(test), thecallbackfunction has not yet been called (it happens later in thereturnstatement).
– Bergi
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value oftestis still the empty string. I'm not sure what is the point though, what are you trying to do?
– Stefan
Nov 24 '18 at 22:50
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51
1
1
Because when you
console.log(test), the callback function has not yet been called (it happens later in the return statement).– Bergi
Nov 24 '18 at 22:50
Because when you
console.log(test), the callback function has not yet been called (it happens later in the return statement).– Bergi
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value of
test is still the empty string. I'm not sure what is the point though, what are you trying to do?– Stefan
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value of
test is still the empty string. I'm not sure what is the point though, what are you trying to do?– Stefan
Nov 24 '18 at 22:50
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51
add a comment |
1 Answer
1
active
oldest
votes
0
You simply need to return test (or string) at the end of your callback function.
The return statement ends function execution and specifies a value to
be returned to the function caller.
Check the below code:
render() {
let test = '';
let callback = (string) => {
test = string;
return test;
}
return (
<div>
{callback("string value")}
</div>
);
}
}
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
0
You simply need to return test (or string) at the end of your callback function.
The return statement ends function execution and specifies a value to
be returned to the function caller.
Check the below code:
render() {
let test = '';
let callback = (string) => {
test = string;
return test;
}
return (
<div>
{callback("string value")}
</div>
);
}
}
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
add a comment |
0
You simply need to return test (or string) at the end of your callback function.
The return statement ends function execution and specifies a value to
be returned to the function caller.
Check the below code:
render() {
let test = '';
let callback = (string) => {
test = string;
return test;
}
return (
<div>
{callback("string value")}
</div>
);
}
}
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
add a comment |
0
0
0
You simply need to return test (or string) at the end of your callback function.
The return statement ends function execution and specifies a value to
be returned to the function caller.
Check the below code:
render() {
let test = '';
let callback = (string) => {
test = string;
return test;
}
return (
<div>
{callback("string value")}
</div>
);
}
}
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
You simply need to return test (or string) at the end of your callback function.
The return statement ends function execution and specifies a value to
be returned to the function caller.
Check the below code:
render() {
let test = '';
let callback = (string) => {
test = string;
return test;
}
return (
<div>
{callback("string value")}
</div>
);
}
}
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
edited Nov 24 '18 at 23:06
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
answered Nov 24 '18 at 22:57
Hassan AlMandilHassan AlMandil
2315
2315
add a comment |
add a comment |
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1
Because when you
console.log(test), thecallbackfunction has not yet been called (it happens later in thereturnstatement).– Bergi
Nov 24 '18 at 22:50
When you call console.log the callback function hasn't been called yet so the value of
testis still the empty string. I'm not sure what is the point though, what are you trying to do?– Stefan
Nov 24 '18 at 22:50
Btw, I don't see any callback function here that would be passed around, it's just a normal local function. Is this your actual code?
– Bergi
Nov 24 '18 at 22:51