web_javascript脚本编程.pdf
8页
JavaScript???? JavaScript????DHTML?Javascript?? DHTML?Javascript ??DHTML????HTML???HTML?????? DHTML????HTML???HTML?????? HTML? ????CSS???????????? HTML????? CSS???????????? ?Javascript???? ??? Javascript??????? Javascript?? ??????????????? Javascript???? ????????????? ???????????? HTML????? ????????????HTML??? ?? Javascript????????????????? Javascript????????????????? ?? ???????????? ???HTML??????? ???????? ???HTML?????????? ????? ???????????????????????????????Javascript? Javascript?JScript ? ECMA ????????????????? ECMA????? ???????????? ??????????ECMA- 262????? ??????????ECMA-262??? ?? ?????????? ? Javascript????? ???? Javascript?????????Javascript?? Javascript????????????HTML???????? ?? ????????HTML???????? ?????? ?????????? ??????????????? ?????? ??????? ??????????? ?????????? ??????????????? ?????? ????? ?????????JavaScript?? JavaScript??JavaScript???????????????? JavaScript???????????????? ??????????????????JS?? ??????? ???????????JS?? ????JavaScript? ???? ????JavaScript??????????Javascript?? ????? Javascript??kk ?????????????Javascript???HTML????? ??????Javascript???HTML????? ?? ??? ????? ??document.write?????? ?????? ??document.write???????? ???? ???????HTML??? ??????? HTML??? Javascript??+ Javascript??+?? ???????????? ????Javascript???? Javascript????1. ?????? ????? ?????10,-2345? ????10,-2345? ?? ???2.12? 3.245?4.87e23? ?????2.12?- 3.245?4.87e23? ?????? ??????hello world”???含hello world’?? world”???含 world’ javascript????c javascript???? c?????????????? ?????????? ???????????? ????????????true??false ????true??false?????????????????????? ?null???????? null?????????????????????? ?????????? ?????????????? ??????????? ??????????????????????????????????? ???????????????javascript???? ???????????????javascript???? ???????????var????? ???????? var?????var mytest??? mytest??? var mytest= 5????javascript????????? mytest= 5????javascript????????? ??c ?? c????????????????????? ??? ??????????????????? var x?x= 5?x=“hello”? x?x=5?x=“hello” ?????? ?????????????????? ??????? ???????????????? ????????? ?????????????? ????????var scope = “global“; function outerFunction() { var scope = “local“; document.write(“The value of scope is: “ + scope);innerFunction(); } function innerFunction() { document.write(“The value of scope is: “ + scope); } outerFunction();?????????3+2=? 3+2=? 3+”2”=? 3+” 3+3+” 3+3+”2” =? ?????????????????? ?????????????Javascript???????????parseInt? Javascript???????????parseInt? parseFloat parseInt? 42” parseInt??42”? =? parseInt(“42.33”)=? parseInt(“42.33” parseFloat(“42” parseFloat(“42”)=? parseFloat(“42.33”)=? parseFloat(“42.33”?????????? +number??? +2500=? ???? ” +number??? ”+2500=? ???????????? ???javascript?? ?????????????? ?javascript?? ???????????????+ ??????+ - * / % ++ -? ?????visibility— none,blcok;visibility— visible,hidden;pixelLeft,pixelTop)IE??????? IE???????IE???????????????????? IE ???????????????????? ????? window?? ?????window?? ???????? ?event???cancelBubble ????????? event???cancelBubble ???true???? event?????????? ???true???? event?????????? ???????ID??????????—options???selectedIndex??? text? ??—options???selectedIndex??? text? value?? value??。
