Basic PHP Learning

Basic PHP Learning

<?php

Type

$test = 123;

Var_dump ($test);//print out type and value

Echo '

echo GetType ($test);//get variable type-"integral type"

Echo '

$res = (bool) $test;//temporary conversion type

Var_dump ($res);//true

Var_dump ($test);//123

Echo '

Settype ($test, ' string ');//change type

Var_dump ($test);//"123"

Echo '

Assign value

Var_dump (

0== $sdfg//null-->0 1+NULL;//1

);

$i = 5;

$i + +;

Echo $I;//6

Echo '

Character connections

$str 1= "Hello";

$str 2. = $str 1; $str 2=null. $str 1;

$str 2. = '! '; $str 2= $str 2. '! ';

Echo $str 2; Hello!

logical operators and && and; or;! Non -

$i = 1;

$j = 0;

Var_dump (

$i && $j//false

$i--&& $--j//true

);

?>

@ Error Suppression symbol, suppressing error output

$var = 1;

@settype ($var, ' King ');

echo @ (4/0);

Die exit: Terminate program execution

Output 99 multiplication table

For ($i =1; $i <=9; $i + +) {

For ($j =1; $j <=9; $j + +) {

Echo "{$i}x{$j}=". ($i * $j). ' ";

}

Echo ' <br/> ';

}

Output a table

The difference between the while and do while

Arrays in PHP

Declaring an array: array ()//[]

Use Principle: find the building value based on the name of the building

Defining an indexed array

$arr = [23,54, ' King ', true];

Print_r ($arr);//print Array

$arr = [

23=> ' a ',

54=> ' B ',

-12=> ' C ',

23=> ' d '

];

Print_r ($arr);

Duplicate name will produce overwrite

Iterate through the array method in Php:

foreach ($arr as $k = = $v) {

Echo $k, $v;

}

Basic PHP Learning