Javascript Parameter With Quotes

Names A name is a letter optionally followed by one or more letters, digits, or underbars. A name cannot be one of these reserved words: abstract boolean break byte case catch char class const continue debugger default delete do double else enum export extends false final finally float for function goto if implements import in instanceof int interface long native new null package private protected public return short static super switch synchronized this throw throws transient true try typeof var volatile void while with Most of the reserved words in this list are not used in the language. The list does not include some words that should have been reserved but were not, such as undefined, NaN, and Infinity. It is not permitted to name a variable or parameter with a reserved word. Worse, it is not permitted to use a reserved word as the name of an object property in an object literal or following a dot in a refinement. Names are used for statements, variables, parameters, property names, operators, and labels.

Think of your body as a program and your organs as functions. Yours organs are the functions, and they communicate by sharing information via variables that are taken as parameter for the organ and they do their own thing and the whole body functions in harmony.

It can be useful for a function to accept any number of arguments. For example, Math.max computes the maximum of all the arguments it is given. To write such a function, you put three dots before the function’s last parameter, like this: function max(... numbers)

We defined square with only one parameter. Yet when we call it with three, the language doesn’t complain. It ignores the extra arguments and computes the square of the first one.

If you write an = operator after a parameter, followed by an expression, the value of that expression will replace the argument when it is not given.

we will see a way in which a function body can get at the whole list of arguments it was passed (see “Rest Parameters” on page 74). This is helpful because it makes it possible for a function to accept any number of arguments.

Strict mode does a few more things. It disallows giving a function multiple parameters with the same name and removes certain problematic language features entirely (such as the with statement, which is so wrong it is not further discussed in this 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