into JavaScript's study.

Learning JavaScript Today, JavaScript is a new description language that can be clamped into HTML files.

JavaScript can be used to respond to the user's needs events (such as the input of a form) without transmitting data back and forth from any network, so when a user enters a data, it does not pass to the server

Processing, and then passing back the process, and directly can be handled by the client application program.

Because yesterday I self-taught some, so the teacher said I do not sound difficult, but still apply, always make a little mistake, or less a parenthesis, or semicolon with the Chinese format,

Cause there is always no effect, or should be more practice, attached to the teacher today to explain the content:

1, three kinds of JS introduction mode
A), <input type= "button" value= "click event" onclick= "document.write (' Hello word! ') ' >
b), <script type= "Text/javascript" >
document.write (' Hello word! ‘)
</script>
c), <script type= "Text/javascript" src= "Js/index.js" ></script>
Note: External reference path to write to
Single double quotes: quotation marks cannot use the same quotation marks

2. Three kinds of pop-up window alter confirm prompt
3. Two types of annotation//single-line comment/* Multiline comment */
4. Define variable var variable name = variable value;
var variable name;
Variable name = variable value;
Note: All are semicolon ended * * * *
5, more than 90 excellent, more than 80 good, more than 60 pass 60 fail
6. If format
if (condition 1) {
Execution of the statement;
}else if (condition 2) {

}
Note: If...else If this is an if
if () {}
if () {}
This is a two if
7. Complete expression on both sides of the logical operator
8, all the symbols in the code are in English state
9. Switch syntax
Switch (variable) {
Case ' specific value ':
Code to execute
Break
Case ' specific value ':
Code to execute
Break
...
}
Example 1:1, the input positive integer n, to seek 1-n and.

var a=prompt ("Please enter a number");
var sum=0;
if (IsNaN (a)) {
document.write ("You are not entering a number")
}else{
for (Var i=0;i<=a;i++) {
Sum=sum+i;
}
}
document.write (sum);
document.write ("<br/>");

Example 2: Enter the score to determine whether the pass, if more than 80 points output "you learn good, worthy of praise!" ", if the output between 50-60 points is a little bit, and then add strength", if less than 50 output "hard work, do not lazy!" ”

var b=prompt ("Please enter your score");
if (b>80) {document.write ("You learn well, deserve praise!") ")}
else if (b>50&&b<60) {document.write ("Just a little bit, and then the Harder")}
else if (b<50) {document.write ("hard work, don't be lazy!") ")}

Example 3:100 staircase, 0-49 knots equal to the number of nodes 50 (including 50) Each section 10 points the number of input sections to score

Num: Number of sections
NUM1: Number of knots-49
Sum Total
if (num<=49) {
for (i <= num)
}else{
NUM1 = num = 49;
for (i <=) {sum1 = SUM1 + i} score sum1
for (I<NUM1) {SUM2 = SUM2 + 10} score sum2
sum = sum1 + sum2
}

Learning to go into JavaScript