Sometimes, when working with the JavaScript programming language, you might encounter the error "Form must be one of." This error usually occurs when you try to submit a form or data that does not comply with the expected format or permitted type.
To understand why this error exists, we first need to comprehend how JavaScript manages data. JavaScript is a language that is recognized due to its ability to manage data dynamically. Thus, if a form or data is not defined correctly or is not properly submitted, this flexibility can lead to a state where it may convert into an error.
This error can occur at times when you want to send data with a specific type or structure to a function that only accepts certain types and structures. If this application does not accept the data, JavaScript will raise this error to inform you that there is an issue with the data format.
Now, let’s see how we can solve this issue using simple code. First, reviewing the data precisely before sending it to the function or parameters is essential. By using the following code snippet, we can examine the type and format of the data:
function validateForm(input) {
const acceptedForms = ['text', 'email', 'number'];
if (!acceptedForms.includes(input.type)) {
throw new Error('Form must be one of: text, email, number');
}
// Continue processing the data...
}
This code is a good example for controlling the type of input. Initially, we define a function named validateForm that receives an input.
Next, we define an array named acceptedForms that contains the allowed types of forms: text, email, number.
By using the includes method from JavaScript, we can check whether the input type is one of the allowed types or not. If this type doesn’t exist, an error message will be displayed indicating that the input type is incorrect.
In summary, if the input type is allowed, the processing function can continue, which here for simplicity is labeled "continue processing the data..." to show data processing.