javascript - use useState to append string values - Stack Overflow

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Hi I want to create a global variable in react but I would like to avoid it, so I created a ponent and want to store string data in it such as below:

export default function settings() {
const [stringData, setStringData] = useState("");

I want this state to concactnate input string. For example

setStringData("I am ");
setStringData(" a ");
setStringData("robot.");

When I retrieve stringData I want it to be printed as

I am
 a
robot.

How do I do this ?

Hi I want to create a global variable in react but I would like to avoid it, so I created a ponent and want to store string data in it such as below:

export default function settings() {
const [stringData, setStringData] = useState("");

I want this state to concactnate input string. For example

setStringData("I am ");
setStringData(" a ");
setStringData("robot.");

When I retrieve stringData I want it to be printed as

I am
 a
robot.

How do I do this ?

• javascript
• reactjs
• global

Share Improve this question Follow asked May 11, 2021 at 7:59 takanohatakanoha 35311 gold badge55 silver badges2121 bronze badges 1

• 1 setStringData(stringData + '\n' + 'whatever') – Roberto Zvjerković Commented May 11, 2021 at 8:03

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 3

When you calling setStringData it is the same as though you just assign a value to a variable, e.g. stingData = 'asdf' so if you need to concatenate strings you need to add the current value and the string you want to add, below you can find an example.

const [stringData, setStringData] = useState("");
setStringData(stringData + "Some Sting To Append!");

UPD: Based on the ments, showing an example with some listener.

const [stringData, setStringData] = useState("");

const addString = () => setStringData(stringData + " Clicked!");

return (<button onClick={addString}> Add Text </button>);

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