Consider the following array:
var john = ['asas','gggg','ggg'];If an attempt is made to access john at index 3, i.e. john[3], it results in an error.
Is there a way to show a message or trigger an alert indicating that there is no value stored in that particular index?
function validateArrayIndex(array, index) {
if (array[index] === undefined){
alert('The index ' + index + ' does not exist!');
return false;
}
return true;
}
// Here is an example of how to use the function:
if(validateArrayIndex(john, 3)) {/* Index exists, now you can perform some action */}
else {/* Index DOES NOT EXIST */}
if (typeof data[missingIndex] === "undefined") {
// This index is undefined
console.log("Missing index: " + missingIndex;
}
One of the features of Javascript is its try catch function.
try {
// Add your code here
} catch(err) {
// Handle the error - err likely contains a specific message as well.
alert("Error");
}
In the world of programming, Javascript arrays always begin at the index 0. Therefore, in your specific array, you have values starting at index 0 - 'asas', index 1 - 'gggg', and index 2 - 'ggg'.
let names = ['John', 'Doe', 'Smith'];
let position = 2;
if (names[position] != undefined ){
console.log(names[position]);
}
Indexes in arrays always begin at 0, not 1.
This specific array contains 4 elements which are listed below:
alex[0] // apples
alex[1] // bananas
alex[2] // oranges
alex[3] // grapes
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