JS Basic Statement

1. Required conditions in the loop: initial value cyclic condition state change loop body
for (initial value loop condition State change)
{
Loop body
}

The use of the for (Var i=0;i<100;i++) {if (i%7==0| | i%10==7| | parseint (I/10) ==7)   parseint is written in the  case {alert (i);  

2. Three-step operator? ：

var s= a==b? " Equal to ":" is not equal to ";

3. Concatenation of Strings +

var str1= "Hellow"; var str2= "table"; var s=str1+str2;confirm (s);  Output hellowtable

4. Forced manual conversion in special places
can only turn integers to decimals

var a= "2";p arseint (a), Var s= "3.2";p arsedouble (s);

5. Summary

1. Basic data type: String, Decimal, Integer, Date time, Boolean, etc. 2, variable: "var" definition variable: var A; all variable definitions are defined with Var, var is a generic mutable type.　　3, type conversion: converted to integers: parseint (); Converted to decimal: parsefloat ();    Case 4, Operator: The operation symbol is basically the same as C #  The only difference is in   C # inside/representing the quotient of the value   and/representation in addition to including the decimal point math operator: +-*/% + +--; relational operator: = = =  >  >=  <  <=; logical operator:&&  | |  ! ; other operators: + = = *=/=%=?: 5, statements: divided into sequential, branching and looping statements. Branch: if () {}else{}       switch () {case:break;} loop: for (;;) {}  Popup: Alert ("Alert"), Cancel Fork confirm ("confirm"), OK to cancel fork prompt ("Please enter Number", "you enter AH"); input OK cancel fork

6. Page Layout Summary

Web Design Summary: 1: The Web design is too non-hierarchical sense, from the back to rush, next time you need to first the overall framework layout, and then the layout of each framework; finally add content; Just like the processing of branch statements, the processing is done from a large scope, processing, processing, and then doing a small scope;2. Details: Each statement is as complete as possible: for example, each div must have at least a length and a width of less than the default area of 0; If you need a background, you can set the background in Boby. Width must be set here (can set to 100%The length is considered to increase with the increase of content;3.style position different effects, mouse trigger when the effect can be in <Style><style>inside individual set of background test4. In the process of modification, if you mistakenly </div> delete the default is added after the <div></div> is included in the last <div>(pay special attention when using the stream)5. If a problem occurs when using the margin function alone, you can firstfloatagain to use;6. Font Settings 7. a:hover a:link a:visited a:activited {not limited to a-label other tags can also be used as a class tag as well as a parallel descendant filter. wer:hover{Backgro und-color:red;    }.wer{width:300px;    height:300px; Background-color: #33F;    Position:absolute;    top:100px; left:100px}

7. Practice the problem of playing the board with Sesame

var sum=0;  for var i=0;i<=32;i++) {  var si=1;       for var j=0; j<i; J + +)    // Note the  n-th square    {     si=si*2   }   sum of 2, starting from 0 + =Si}alert (0.00001*sum)

View Code

var t=0.00001; var sum;  for var i=1;i<=32; i++) {       if(i==1)    {     sum=t;    }     if (i>1)    {        T=2*t;        Sum+ =t;        }} Alert ("total weight" +sum);p rompt ("Prompt", "you enter Ah");

method Two: List the first month as a special case separately

JS Basic Statement