Operators
Assignment operators to assign values to variables. y = 5; / z = 2;
That arithmetic operators arithmetic symbols, the basic arithmetic operation. + Add / - subtraction / multiplication * / / addition /% fetch I / ++ increment (Y + assignment first and then the self-energizing / + Y increment and then the first assignment) / - decrement and increment empathy /
Compound operator + = x + = y plus other equivalent x = x + y The other principle / - + etc. Save / * = multiplication and other / / = the like in addition / modulo% = like
Base Event
Element by using the acquired ID: var leroy = document.getElementById ()
Get var leroy = document.getElementByClass () by some other method for obtaining class of ...
Onclick event click event
var leroy=document.getElementById()；
leroy.onclick=function(){ alert(); }
onmouserover mouse moved events
leroy.onmouserover =function(){ alert(); }
onmouseout event mouse out events
leroy.onmouserout =function(){ alert(); }
Boolean type
Or called Boolean Boolean data type is a base only two values 'true' or 'false'
The general relationship operator returns a Boolean value result, the value of special worth 0-0 null NaN undefined and null characters ( "") will be translated into other false value is interpreted as true
Relational operators perform a comparison operation
> Greater than / <less than /> = Greater than or equal to / <= less / equal == / === congruent /! = Ranged /! == full range
Uppercase character encoding all less than lowercase character encoding
Letter "a" can not be converted to a reasonable value, the turn is NaN. Any value to compare the relationship between NaN, the result is false.
<, <=,>,> = The same four budget precedence. /
==,! =, ==,! == four operators have the same priority.
The first four operator has higher precedence than the four operands. Relational operators lower precedence than arithmetic operators. Relational operators higher priority than assignment operator
Logical operator for logical relationship between the measured variables or values
&& and / or || /! Non
if statement conditional statement to perform different actions for different conditions
Only when a specified condition is true, will execute code
if (condition) {conditions must be true}
if (condition) {code is executed when the condition is true} condition is not performed when the else {true} code
if (condition) {XXXXX} else if (condition 2) {condition 2 is true when the execution code} else {xxxx}
The switch statement is used to perform different actions in different conditions
switch(n)
{
case1: executed 1
break;
case2: execute 2
break;
default: not simultaneously with case1 and case2;}
Ternary operator
var name=(condition)?value1:value2;
var n = 1 var car = (n == 1) 'Monday': 'Tuesday';?
onload event is generally used when writing code execution in the head after the page loads to keep the script content affected
window.onload=function(){
alert();
}
Therefore, we generally will script code in the bottom of the page, so that when running the script code, you can ensure that the objects to be manipulated has finished loading. To execute script code by window.onload.
for loop code can be specified in the execution block Shu
for (single expression; conditional expression; the end of the loop) the loop body {intermediate;}
There LeRoy = o
for(var i=0;i<100;i++){ document.write(leroy.i+"<br>");}
JavaScript support different types of loops:
for - a certain number of cycles code block
for / in - loop through the properties object
while - when a specified condition is true cycle specified code block
do / while - when the code block of the same specified condition is true cycle specified