Home > Article > Web Front-end > Why is my variable empty when I try to get the value from an input field?
Empty Input Value Stored in Variable: Causes and Solutions
When attempting to access the value property of an input field for data retrieval, users may encounter an issue where the stored variable remains empty. This article explores the causes and provides solutions to address this problem.
The issue stems from the fact that when a JavaScript variable is assigned the value property of an input element, it stores a snapshot of that value at the time of assignment. As a result, subsequent changes made to the input element's value are not reflected in the variable.
Solution 1: Query the Element on Button Click
One solution to this issue is to query the input element within the button's click event handler. This ensures that the input value is retrieved and stored in the variable each time the button is clicked.
const testing = () => { const inputValue = document.getElementById("inputField").value; alert(inputValue); };
Solution 2: Reference the Input Element
Alternatively, you can create a reference to the input element and then access its value property within the click event handler. This approach avoids unnecessary repeated DOM queries.
const inputElement = document.getElementById("inputField"); const testing = () => alert(inputElement.value);
By implementing these solutions, you can ensure that the input value is always up-to-date, allowing for the proper retrieval and processing of data from the desired API URL.
The above is the detailed content of Why is my variable empty when I try to get the value from an input field?. For more information, please follow other related articles on the PHP Chinese website!