javascript-Notes.html

<script>
function lowerCase(input) {
return typeof input === "string" ? input.toLowerCase() : false
// if (typeof input === "string")
//     return input.toLowerCase()
// else {
//     return false
// }
}

function isAllLowerCase(input) {
return input === String(input).toLowerCase()
}

function isAllUpperCase(input) {
return input === String(input).toUpperCase()
}

function isNotPalindrome(input) {
if (input === undefined || input === null) {
return true;
}

if (typeof input !== 'string') {
input = String(input);
}

input = input.toLowerCase();

return input !== input.split('').reverse().join('');
}


function multiplyBy2(input) {
if (typeof input === 'string') {
input = parseFloat(input);
}

if (typeof input !== 'number' || isNaN(input)) {
return false;
}

return input * 2;
}

function convertHourToSec(input) {
if (typeof input === 'string') {
input = parseFloat(input);
}
if (typeof input !== 'number' || isNaN(input) || input < 0) {
return false;
}
return input * 60 * 60
}

function getLowestNumber(num1, num2, num3) {
if (
isNaN(parseFloat(num1)) ||
isNaN(parseFloat(num2)) ||
isNaN(parseFloat(num3))
) {
return false;
}
num1 = parseFloat(num1);
num2 = parseFloat(num2);
num3 = parseFloat(num3);
return Math.min(num1, num2, num3);
}


function addStringLengths(str1, str2) {
if (typeof str1 === 'undefined' || typeof str2 === 'undefined' || str1 === null || str2 === null || typeof str1 === 'boolean' || typeof str2 === 'boolean' || typeof str1 === 'number' || typeof str2 === 'number' || typeof str1 === 'object' || typeof str2 === 'object' || Array.isArray(str1) || Array.isArray(str2)) {
return false;
}

return str1.length + str2.length;
}


function subtract(a, b) {
if (typeof a === 'undefined' || typeof b === 'undefined' || a === null || b === null || typeof a === 'boolean' || typeof b === 'boolean' || isNaN(Number(a)) || isNaN(Number(b))) {
return false;
}

return Number(a) - Number(b);
}


// function calculateChange(totalAmount, amountPaid) {
//     let change = totalAmount - amountPaid
//     if (typeof totalAmount === 'undefined' || typeof amountPaid === 'undefined' || typeof totalAmount === null || typeof amountPaid === null || typeof totalAmount === 'boolean' || typeof amountPaid === 'boolean')
//         return false;
//     else {
//         return `$ ${change.toFixed()}`
//     }
//
// }

// function calculateChange(amount, price) {
//     if ( typeof amount !== "number" || typeof price !== "number") {
//         return false;
//     }
//     const change = amount - price;
//      return '$' + change.toFixed(2);
// }
function calculateChange(amount, price) {
if (typeof amount !== "number" || isNaN(amount) || typeof price !== "number" || isNaN(price)) {
return false;
}

const change = amount - parseFloat(price);
return '$' + change.toFixed(2);
}

</script>