diff options
Diffstat (limited to 'javascript.html.markdown')
| -rw-r--r-- | javascript.html.markdown | 32 | 
1 files changed, 22 insertions, 10 deletions
| diff --git a/javascript.html.markdown b/javascript.html.markdown index 34ba9b47..a119be88 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -54,6 +54,11 @@ doStuff()  // Including uneven division.  5 / 2; // = 2.5 +// And modulo division. +10 % 2; // = 0 +30 % 4; // = 2 +18.5 % 7; // = 4.5 +  // Bitwise operations also work; when you perform a bitwise operation your float  // is converted to a signed int *up to* 32 bits.  1 << 2; // = 4 @@ -104,7 +109,7 @@ null == undefined; // = true  // ...unless you use ===  "5" === 5; // = false -null === undefined; // = false  +null === undefined; // = false  // ...which can result in some weird behaviour...  13 + !0; // 14 @@ -144,6 +149,10 @@ someOtherVar = 10;  // Variables declared without being assigned to are set to undefined.  var someThirdVar; // = undefined +// if you wan't to declare a couple of variables, then you could use a comma  +// separator +var someFourthVar = 2, someFifthVar = 4; +  // There's shorthand for performing math operations on variables:  someVar += 5; // equivalent to someVar = someVar + 5; someVar is 10 now  someVar *= 10; // now someVar is 100 @@ -220,15 +229,15 @@ for (var i = 0; i < 5; i++){  //The For/In statement loops iterates over every property across the entire prototype chain  var description = ""; -var person = {fname:"Paul", lname:"Ken", age:18};  +var person = {fname:"Paul", lname:"Ken", age:18};  for (var x in person){      description += person[x] + " ";  } -//If only want to consider properties attached to the object itself,  +//If only want to consider properties attached to the object itself,  //and not its prototypes use hasOwnProperty() check  var description = ""; -var person = {fname:"Paul", lname:"Ken", age:18};  +var person = {fname:"Paul", lname:"Ken", age:18};  for (var x in person){      if (person.hasOwnProperty(x)){          description += person[x] + " "; @@ -282,12 +291,9 @@ myFunction("foo"); // = "FOO"  // Note that the value to be returned must start on the same line as the  // `return` keyword, otherwise you'll always return `undefined` due to  // automatic semicolon insertion. Watch out for this when using Allman style. -function myFunction() -{ +function myFunction(){      return // <- semicolon automatically inserted here -    { -        thisIsAn: 'object literal' -    } +    {thisIsAn: 'object literal'}  }  myFunction(); // = undefined @@ -301,6 +307,12 @@ setTimeout(myFunction, 5000);  // Note: setTimeout isn't part of the JS language, but is provided by browsers  // and Node.js. +// Another function provided by browsers is setInterval +function myFunction(){ +    // this code will be called every 5 seconds +} +setInterval(myFunction, 5000); +  // Function objects don't even have to be declared with a name - you can write  // an anonymous function definition directly into the arguments of another.  setTimeout(function(){ @@ -319,7 +331,7 @@ i; // = 5 - not undefined as you'd expect in a block-scoped language  // scope.  (function(){      var temporary = 5; -    // We can access the global scope by assiging to the "global object", which +    // We can access the global scope by assigning to the "global object", which      // in a web browser is always `window`. The global object may have a      // different name in non-browser environments such as Node.js.      window.permanent = 10; | 
