var myMap = {};
myMap[newKey] = newValue;
// ...
// Another method
var myMap = new Map()
myMap.set("key0","value")
// ...
myMap.has("key1"); // evaluates to false, assuming key1 wasn't set
Here is what the above code is Doing:
1. We create a new Map object called myMap.
2. We add a key-value pair to myMap using the set() method.
3. We check if myMap has a key called key1 using the has() method.
let props = condition ? {tabIndex: 1} : {}; let div = Here is what the above code is Doing: 1. We’re creating a variable called condition and setting it to true. 2. We’re creating a variable called props and setting it to an object literal. 3. If condition is true, we’re setting tabIndex to…
$(“#yourElement”).after(“Element was there”).appendTo(“body”); Here is what the above code is Doing: 1. It’s checking to see if the element with the ID of yourElement exists. 2. If it does, it adds a paragraph tag with the text “Element was there” after the element. 3. It then appends the element to the body of the page.
var win = window.open(‘http://stackoverflow.com/’, ‘_blank’); if (win) { //Browser has allowed it to be opened win.focus(); } else { //Browser has blocked it alert(‘Please allow popups for this website’); } Here is what the above code is Doing: 1. It opens a new window with the URL http://stackoverflow.com/ 2. If the window is successfully opened,…
const input = wrapper.find(‘#resize_thumbs_input’) input.element.value = 100 input.trigger(‘input’) Here is what the above code is Doing: 1. Find the input element with the id of ‘resize_thumbs_input’ 2. Set the value of the input to 100 3. Trigger the ‘input’ event on the input element
Math.hypot(x2-x1, y2-y1) Here is what the above code is Doing: 1. We’re creating a function called distance that takes in two parameters, x1 and y1. 2. We’re creating a variable called x2 and setting it equal to 0. 3. We’re creating a variable called y2 and setting it equal to 0. 4. We’re creating a…
// Check document.getElementById(“checkbox”).checked = true; // Uncheck document.getElementById(“checkbox”).checked = false; Here is what the above code is Doing: 1. We select the checkbox using the id attribute. 2. We set the checked property to true or false.