To Compare Float, Double, or Long Data Types

A way to make doubles, floats, or longs ‘equal’.

Float a=1.56148; Float b=1.56139;
  Float threshold = 0.00009 or 0.0001 //difference of Float a and Float b
  if (Math.abs(a-b) <= threshold){//Or < threshold
     //logic here
  }

Regex basics

function stringSearch(){
    var str="HTML5 javascript CSS JSON?";

    //Define search funciton and outputting the string
    //A spacing is also one of the index in regExp
    document.getElementById("content").innerHTML="search 1: 
    "+str.search('j')+"search 2: "+//If not found, returns -1
 

PHP Basics: Very Basic Syntax

<?
   //Short
   /**Need to set short open in localhost settings*/
   echo 'hello world';

   //echo means output text
?>
 

PHP Basics: Variables

<?php
   //PHP is sensitive to upercases and lowercases   
   $a=2;
   /**Print out all the variables those
   have the same values assigned together*/
   $name='s';
 

PHP Basics: Passing by Reference

PHP allows 2 variables to point to 1 value

<?php
   $a=10;
   $b=&$a;//$b and $a
 

PHP Basics: Data Types

PHP data types explained using simple sample code

<?php
   $a=5; //echo $a;
   $b=25.6;
   echo var_dump($a);
   echo var_dump($b);
   $c=true;
 

PHP Basics: Database Juggling 1

<?php
   $a=true+1;//true's value is 1
   echo $a;
   $b=false+1;//false's value is 0
   echo $b;
   echo null+1;
   $str=1+'abcd';
 

PHP Basics: Database Juggling 2

<?php
   //Force to juggle Datatypes
   $a=123;
   $b=1.2;

    //use functions to implement temporarily juggling
   echo var_dump((string)$a);
   echo var_dump((bool)$a);
 

PHP Basics: Constants

<?php 
    echo PHP_VERSION;
    echo PHP_OS;
    echo M_PI;
 

PHP Basics: Operators

<?php
//Operators
  $a=1;
  $b=2;
  echo '1+2=',$a+$b;
  $a=10;