Array Javascript Quotes

var books = new Array(new Book(), new Book(), new Book());

suppress empty strings in the output array when the separator is a regular expression: var f = '|a|b|c|'.split(/\|/); // f is ['a', 'b', 'c'] on some systems, and // f is ['', 'a', 'b', 'c', ''] on others string.substring(start, end ) The substring method is the same as the slice method except that it doesn’t handle the adjustment for negative parameters. There is no reason to use the substring method. Use slice instead. string.toLocaleLowerCase( ) The toLocaleLowerCase method produces a new string that is made by converting this string to lowercase using the rules for the locale. This is primarily for the benefit of Turkish because in that language `I’ converts to 1

Note that the JSON format doesn’t work with methods (so you can’t include, say, a bark method in your JSON string), but it does work with all the primitive types, as well as objects and arrays.

Q: Q: You said getElementsByTagName returns a list. Do you mean an array? A: A: It returns an object that you can treat like an array, but it’s actually an object called a NodeList. A NodeList is a collection of Nodes, which is just a technical name for the element objects that you see in the DOM tree. You

You can use a similar three-dot notation to call a function with an array of arguments. let numbers = [5, 1, 7]; console.log( max(... numbers)); // → 7 This “spreads” out the array into the function call, passing its elements as separate arguments. It is possible to include an array like that along with other arguments, as in max( 9, ... numbers, 2).

With the handy map method of arrays (introduced in ES5), we can completely eliminate the loop details, implementing just the element-by-element transformation with a local function: Click here to view code image var names = [" Fred", "Wilma", "Pebbles"]; var upper = names.map( function( name) { return name.toUpperCase(); });

// Arrays var trees = ['elm', 'ash', 'cedar', 'poplar', 'maple']; 0 in trees; // will return true 3 in trees; // will return true 6 in trees; // will return false 'ash' in trees;    // will return false (the index number must be specified,

When you pass a primitive value it is copied into the parameter. We call this “passing by value.” So if you change the value of the parameter in your function body it has no affect on our original argument’s value. The exception to this is passing an array or object, and we’ll get to that in a bit.