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Javascript Unique Syntax

Posted on October 15, 2013 | Tags:

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This post is only means for my references, but maybe useful for you

1. Boolean Shorthand Replacement

// Normal
true, false

// Shorthand
!0, !1

// Because true === !0, false === !1

2. Convert to Number

var a = "1";

// Normal
new Number( a );

// Shorthand
+a;

// Result 1

3. Convert to fixed Number

var a = 3.5;

// Normal :
parseInt( a, 10 );

// Shorthand
~~a;

// Result 3

4. Clever way to boolean check if something bigger than -1

var array = [ "a", "b", "c", "d" ];

// Normal
if ( array.indexOf('a') > -1 )

// Alternative
if ( !!~array.indexOf('a') )

// Result true

5. Chain operations with comma

// Normal
function a() {
  if ( true ) {
    window.location.hash = 'page1';
    return true;
  } else {
    return false
  }
}

// Shorthand
function a() {
  return ( true ? ( window.location.hash = 'page1', !0 ) : !1 );
}

// Result true

6. Using [object Array].length to increment its array

var array = new Array();

// Normal
for ( var i=0; i<6; i++) {
  array[i] = i;
}

// Alternative
for ( var i=0; i<6; i++) {
  array[array.length] = i;
}

// Result [1,2,3,4,5,6]

7. Alternative for switch-case

var something = 1;

// Normal
switch( something ) {
  case: 1
   return "a";
  case: 2
   return "b";
  case: 3
   return "c";
  default:
   return "d";
}

// Alternative
var case = {
  1: "a",
  2: "b",
  3: "c",
  def: "d"
}

return case[ something ] || case.def;

8. Short function calling

var a = 1;
function b() { return "b"; }
function c() { return "c"; }

// Normal
if ( a === 1 ) {
  b();
} else {
  c();
}

// Shorthand
( a === 1 ? b : c )();

Any others?

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