I want to render certain action upon button click.
The condition is: (If value exists in input field, then write 'value exists'. If value doesn't exists, then alert).
I tried to replace undefined with null. I also try to replace operator === and ==. None works! Please help.
<html>
<head>
</head>
<body>
<input id='typer' type='text'></input>
<button onclick='hey()'>click</button>
<p id='pw'></p>
<script>
var pw
pw = document.querySelector('#pw');
function hey() {
if (document.getElementById('typer').value !== undefined) {
pw.innerHTML = 'value exists';
} else {
alert('value does not exists');
}
}
</script>
</body>
</html>
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