13 golang中流程控制if else for基本使用125分17秒语言

TOC\o"1-1"\h\z\u Goifforswitchgoto主要是为了简化代码、降低重复ifif1elseif2}注意：Goif匹配的左括号{if和表达式放在同一行，{放在其他位置会触else匹配的{else写在同一行，elseif或elseif右边的大括号在同一行。funcfunc{score:=ifscore>={}elseifscore>{}else}}ifif表达式之前添加一个执行语句，再根据变量值ififscore:=56;score>={}elseifscore>{}else}packagepackagemainimport"fmt"funcmain()ifscore:=56;score>={}elseifscore>{}else}fmt.Println(score)//undefined:}varn1int=varn1int=20varn2int=55varmaxintifn1>n2max=}elsemax=}fmt.Println("max=",for初始语句;条件表达式;}forfori:=0;i<10;i++ii:=for;i<10;{}ii:=fori<10}for}

kk:=for{//for;;{ifk<=10fmt.Println("ok~~",}elsebreak//breakfor}}forfori:=0;i<50;{ifi%2==0}}countcount:=sum:=fori:=1;i<100;{ifi%9==0sum+=i}}练习：1+2+3+4100sumsum:=fori:=0;i<=100;{sum+=}fmt.Println("sum=",varvarn=5sum:=fori:=1;i<=n;{sum*=}fmt.Println("sum=",forfori:=1;i<=12;i++ifi%4==0}}lineline:=num:=fori:=1;i<=line;i++{forj:=0;j<num;j++{}}*lineline:=fori:=1;i<=line;{forj:=0;j<i;{}} forfori:=1;i<=9;i++{forj:=1;j<=i;j++{fmt.Printf("%vx%v=%v\t",i,j,}}range遍历的返回值有以下规律：strstr:="abc上海forindex,val:=range{fmt.Printf("index=%d,val=%c\n",index,}str:="abc上海for_,val:=range{fmt.Printf("val=%c\n",5、switch练习：判断文件类型,如果后缀名是.htmltext/html,如果后缀名.csstext/css如果后缀名是.js输出text/javascriptextnameextname:=switchextnamecasecasecase}extnameextname:=".a"switchextname{casecase".css":case".js":}nn:=switchncase1,3,5,7,case2,4,6,8:}switchswitchn:=7;ncase1,3,5,7,case2,4,6,}ageage:=switchcaseage<caseage>25&&age<=60:caseage>}switchfuncfunc{s:=switchcases==cases==cases==}}varvarnumint=10 {casefallthrough默认只能穿透一层case20:case}Gobreakbreakswitch（开关语句）caselabelbreak1switch（开关语句）caseextnameextname:=switchextnamecasecasecase}packagepackagemainimportfuncmain()fori:=0;i<2;i++forforj:=0;j<10;j++ifj==2fmt.Println("ij的值",i,"-",kk:=for{//for;;{ifk<=10fmt.Println("ok~~",}elsebreak//breakfor}}3labelbreakpackagepackagemainimportfunc{fori:=0;i<2;i++{forj:=0;j<10;j++{ifj==2break}fmt.Println("ij的值",i,"-",}}}packagepackagemainimport"fmt"funcmain()fori:=0;i<2;i++{forj:=0;j<4;{ifj==2}fmt.Println("ij的值",i,"-",}}}ij0-0ij0-1ij0-3ij1-0ij1-1ij1-3packagepackageij0-0ij0-1ij1-0ij1-1goto语句通过标签进行代码间的无条件跳转。goto语句可以在快速跳出循环、避免重复退出上有一定的帮助。Go语言中使用goto语句能简化一些代码的实现过程。packagepackagemainimport"fmt"funcmain()varnint=30ifn>20{goto}d:\golang\src\demo01>gorunmain.gopackagepackagemainimportf