Based on the 02.JavaScript

Operator

Arithmetic: + Plus, minus, * multiply,/divide,% modulo example: interlaced color, seconds turn time
Assignment values: =, + =,-=, *=,/=,%=
Relationships:<, >, <=, >=, = =, = =,! = (unequal),!==
Logical:&& with (and), | | Or! No example: Select All and reverse selection
Operator Precedence: parentheses

arithmetic : + Plus, minus, * multiply,/divide,% modulo (take remainder)
Alert (12%5) Popup 2 fetch remainder
Interlaced discoloration (modulus)

<script>window.onload=function (){    varAli=document.getelementsbytagname (' Li ');  for(vari=0;i<ali.length;i++)    {        //I 0 1 2 3 4 5 6 ... ..        if(i%2==0)        {            //0 2 4 6 8Ali[i].style.background= ' #CCC '; }        Else        {            //1 3 5) 7 9Ali[i].style.background= "; }    }};</script><ul> <li></li> <li></li> <li></li> <li></li&    Gt    <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li></ul>

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Seconds calculation

<script>var s=1345; alert (parseint (s/60) + ' +s%60+ ' seconds ');</script>

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Assignment values : =, + =,-=, *=,/=,%=

I=i+1
I+=1
i++ are self-increasing but + + can only add 1 at a time

I=i+3
I+=3 Add 3 each time

relationships :<, >, <=, >=, = =, = =,! = (unequal),!==

logical :&& with (and), | | Or! No example: Select All and reverse selection
! Take counter

Alert (TRUE); The Popup is True
alert (!true); The pop-up is false
Alert (!! true); The Popup is True

Program Flow Control

Judgment: If, switch,? Tri-Wood operation:
Loops: while, for
Jump: Break broken terminal, continue continue
What is true and what is false:
true: true, non-0 numeric, non-empty string such as (' ') has a space , non-empty object summary: There's something real .
False: false, number 00, empty string For example ("'), null for empty object, undefined summary: nothing is fake.

if (condition) {statement 1}else{Statement 2}
if (condition 1) {statement 1}else if (condition 2) {statement 2}else if (condition 3) {statement 3}......else{Statement n} can have countless else if{}, but only one else{}

Switch (variable)
{
Case value 1:
Statement 1
Break
Case Value 2:
Statement 2
Break
......
Default
Statement n
}

<script>var name= ' Blue '; var sex= '; Switch (Sex) {    case ' man ':        alert (name+ ' Mr. Hello ');           Break ;      Case ' Woman ':        alert (name+ ' lady, hello ');          Break ;     default :        alert (name+ ' Hello ');} </script>

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Trinocular operator
Condition? Statement 1: Statement 2 is equivalent to if (condition) {statement 1}else{Statement 2}

<script>var a=14; /* if (a%2==0) {    alert (' Even-numbered ');} else{    alert (' singular ');} */ a%2==0?alert (' Even-numbered '): alert (' singular '); </script>

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Break interrupted
Continue continue

<script>for (var i=0;i<5;i++) {if(i==2) {//  break;    The entire cycle was interrupted      only to eject 0 1 behind the terminals of the continue;    // This cycle is interrupted     only pop-up 0 1 3 4 Only this time the one jumped off }alert (i);} </script>

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What is JSON

JSON format json={Name: value, Name: value, First name: value}

<script>/*var a=12;var b=5;var c= ' abc '; */ var json={a:12, B:5, C: ' abc '};json.b+ +; alert (json.b); </script>

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The difference between JSON and array

var json={a:12, B:5, c:7};
var arr=[12, 5, 7];

Alert (JSON.A)//equals alert (json[' a ');
Alert (arr[0]);

Compare the differences between the two
Alert (json[' a ');.
Alert (arr[0]);
The subscript of the JSON is the subscript of the string array is the number
alert (arr.length); Get is 3
alert (json.length); Get is undefined no length

Array loops
The first loop of an array
for (Var i=0;i<arr.length;i++)
{
Alert (' +i+ ' thing: ' +arr[i]);
}

The second loop of the array
for (var i in arr)
{
Alert (' +i+ ' thing: ' +arr[i]);
}
JSON loop

for (var i in JSON)
{
Alert (' +i+ ' thing: ' +json[i]);
}

There are two loops in the array and JSON loop array with only one loop

Based on the 02.JavaScript