JAVASCRIPT
Dynamically Managing Form Input Values with JavaScript
Learn to programmatically get and set values for various HTML form input types like text fields, checkboxes, and radio buttons using JavaScript.
<form id="myForm">
<label for="textInput">Text Input:</label>
<input type="text" id="textInput" value="Initial Text"><br><br>
<label for="selectOption">Select Option:</label>
<select id="selectOption">
<option value="option1">Option 1</option>
<option value="option2">Option 2</option>
<option value="option3">Option 3</option>
</select><br><br>
<label>
<input type="checkbox" id="checkboxInput" checked> Checkbox
</label><br><br>
<p>Radio Buttons:</p>
<label>
<input type="radio" name="radioGroup" value="radioA"> Radio A
</label>
<label>
<input type="radio" name="radioGroup" value="radioB" checked> Radio B
</label>
<label>
<input type="radio" name="radioGroup" value="radioC"> Radio C
</label><br><br>
<button type="button" id="getValueBtn">Get All Values</button>
<button type="button" id="setValueBtn">Set New Values</button>
</form>
<div id="output"></div>
<script>
const textInput = document.getElementById('textInput');
const selectOption = document.getElementById('selectOption');
const checkboxInput = document.getElementById('checkboxInput');
const radioButtons = document.querySelectorAll('input[name="radioGroup"]');
const outputDiv = document.getElementById('output');
document.getElementById('getValueBtn').addEventListener('click', () => {
const values = {
text: textInput.value,
select: selectOption.value,
checkbox: checkboxInput.checked,
radio: Array.from(radioButtons).find(radio => radio.checked)?.value || 'None selected'
};
outputDiv.textContent = 'Current Values: ' + JSON.stringify(values, null, 2);
console.log('Current Values:', values);
});
document.getElementById('setValueBtn').addEventListener('click', () => {
// Set new values
textInput.value = 'New Text Value';
selectOption.value = 'option3';
checkboxInput.checked = false; // Uncheck it
// Set a different radio button
Array.from(radioButtons).forEach(radio => {
if (radio.value === 'radioC') {
radio.checked = true;
} else {
radio.checked = false;
}
});
outputDiv.textContent = 'Values have been set!';
console.log('Values updated programmatically.');
});
</script>
How it works: This snippet demonstrates how to programmatically get and set values for various HTML form input types. For `text`, `select`, and `textarea` elements, their value is accessed via the `value` property. For `checkbox` inputs, the `checked` property (a boolean) determines its state. For `radio` buttons, you typically iterate through the group (identified by their common `name` attribute) to find which one has its `checked` property set to `true`, or to set a specific radio button to `checked`.