{"id":284,"date":"2020-02-10T22:56:20","date_gmt":"2020-02-10T14:56:20","guid":{"rendered":"https:\/\/www.notown.club\/?p=284"},"modified":"2020-04-05T22:24:29","modified_gmt":"2020-04-05T14:24:29","slug":"ecmascript%e6%ad%a3%e5%88%99%e8%a1%a8%e8%be%be%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/www.notown.top\/?p=284","title":{"rendered":"ECMAScript\u6b63\u5219\u8868\u8fbe\u5f0f"},"content":{"rendered":"\n

\u6b63\u5219\u8868\u8fbe\u5f0f\u4e3b\u8981\u7528\u4e8e\u67e5\u8be2\u3001\u68c0\u7d22\u6216\u66ff\u6362\u6240\u6709\u7b26\u5408\u67d0\u4e2a\u6a21\u5f0f\uff08\u89c4\u5219\uff09\u7684\u6587\u672c\u3002\u56e0\u6b64\u6b63\u5219\u8868\u8fbe\u5f0f\u5176\u5b9e\u5c31\u662f\u4e00\u79cd\u6587\u672c\u6a21\u5f0f\uff0c\u8fd9\u79cd\u6a21\u5f0f\u7528\u4e8e\u63cf\u8ff0\u5728\u641c\u7d22\u6587\u672c\u65f6\u8981\u5339\u914d\u7684\u4e00\u4e2a\u6216\u591a\u4e2a\u5b57\u7b26\u4e32\u3002<\/p>\n\n\n\n

\u4e00\u822c\u6765\u8bb2\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\u662f\u7531\u666e\u901a\u5b57\u7b26\uff08a~z\uff0cA~Z\u7b49\uff09\u3001\u6570\u5b57\uff080~9\uff09\u4ee5\u53ca\u4e00\u4e9b\u7279\u6b8a\u5b57\u7b26\uff08”\\”,”|”,”*”,”^”,”$”,”?”,”!”\u7b49\uff09\u7ec4\u5408\u800c\u6210\u7684\u4e00\u79cd\u903b\u8f91\u516c\u5f0f\uff0c\u5176\u8868\u793a\u5177\u6709\u4e00\u5b9a\u89c4\u5219\u7684\u5b57\u7b26\u4e32\uff0c\u5e76\u901a\u8fc7\u89c4\u5219\u6765\u8fbe\u5230\u8fc7\u6ee4\u6587\u672c\u7684\u76ee\u7684\u3002\u5728ECMAScript\u8bed\u6cd5\u89c4\u8303\u4e2d\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\u662f\u4ee5\u4e00\u4e2aRegRxp\u5bf9\u8c61\u6765\u5b9e\u73b0\u7684\u3002<\/p>\n\n\n\n

\u4e09\u79cd\u5b9a\u4e49 RegRxp\u5bf9\u8c61 \u7684\u65b9\u5f0f\uff1a<\/p>\n\n\n\n

1\u3001var abc=new RegExp(pattern,attributes);<\/code>
pattern\u53ef\u4ee5\u662f\u6b63\u5219\u8868\u8fbe\u5f0f\u6216\u8005\u662f\u5b57\u7b26\u4e32\uff0cpattern\u662f\u6b63\u5219\u8868\u8fbe\u5f0f\u65f6\uff0cattributes\u53c2\u6570\u9700\u8981\u7701\u7565
2\u3001var abc= RegExp(pattern,attributes);
3\u3001var abc=\/pattern\/arributes<\/code>
<\/p>\n\n\n\n

test(),exec(),complie()\u4e09\u4e2a\u51fd\u6570\u7684\u4f7f\u7528\u65b9\u6cd5<\/p>\n\n\n\n

test():\u68c0\u6d4b\u4e00\u4e2a\u5b57\u7b26\u4e32\u662f\u5426\u5339\u914d\u67d0\u4e2a\u6a21\u5f0f\uff0c\u5e76\u6839\u636e\u68c0\u7d22\u7ed3\u679c\u8fd4\u56de\u4e00\u4e2a\u5e03\u5c14\u503c
var strtxt=\"Hello EcmaScript!\";
var reg1=new RegExp(\"EcmaScript\");
var result1=reg1.test(strtxt);<\/code>
\u5219result1\u5f97\u5230true<\/p>\n\n\n\n

exec()\uff1a \u68c0\u6d4b\u4e00\u4e2a\u5b57\u7b26\u4e32\u662f\u5426\u5339\u914d\u67d0\u4e2a\u6a21\u5f0f\uff0c\u5e76\u6839\u636e\u68c0\u7d22\u7ed3\u679c\u8fd4\u56de\u68c0\u7d22\u5230\u7684\u5185\u5bb9
var strtxt=\"Hello EcmaScript!\";
var reg2=new RegExp(\"EcmaScript\");
var result2=reg2.exec(strtxt); <\/code>
\u5219 result2 \u5f97\u5230 “EcmaScript” <\/p>\n\n\n\n

compile(): \u7528\u4e8e\u5728\u811a\u672c\u6267\u884c\u8fc7\u7a0b\u4e2d\u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u4e5f\u53ef\u4ee5\u7528\u4e8e\u6539\u53d8\u548c\u91cd\u65b0\u7f16\u8bd1\u6b63\u5219\u8868\u8fbe\u5f0f
var strtxt=\"Hello EcmaScript!\";
var reg3=new RegExp(\"EcmaScript\");
reg3.compile(\" ecmaScript \");
var result3=reg3.exec(strtxt); <\/code>
\u5219result3\u5f97\u5230false<\/p>\n\n\n\n

RegExp\u5bf9\u8c61\u4fee\u9970\u7b26\u6807\u8bb0<\/p>\n\n\n\n

\u201cg\u201d\u4fee\u9970\u7b26\u6807\u8bb0\u7528\u4e8e\u5b9a\u4e49\u6b63\u5219\u8868\u8fbe\u5f0f\u5bf9\u8c61\u662f\u5426\u6267\u884c\u5168\u5c40\u68c0\u7d22
var strtxt=\"EcmaScript EcmaScript EcmaScript\";
var reg1=\/Ecma\/;
reg1.exec(strtxt);
var i=reg1.lastIndex;<\/code>
i\u4e3a0\uff0clastIndex\u53ef\u5f97\u5f53\u524d\u68c0\u7d22\u4f4d\u7f6e\uff0c\u5373\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u7684exec\u53ea\u4f1a\u68c0\u7d22\u51fa\u7b2c\u4e00\u4e2aEcma\u5e76\u8fd4\u56de\uff0c\u7136\u540e\u68c0\u7d22\u4f4d\u7f6e\u91cd\u65b0\u5f520\uff1b
var reg2=\/Ecma\/g;
reg2.exec(strtxt);
var j=reg2.lastIndex;<\/code>
j\u4e3a4\uff0c\u5373\u7528g\u4fee\u9970\u65f6\uff0c\u80fd\u5168\u5c40\u68c0\u7d22\uff0c\uff0c\u68c0\u7d22\u51fa\u7b2c\u4e00\u4e2aEcma\u540e\uff0c\u68c0\u7d22\u4f4d\u7f6e\u4e0d\u5f52\u96f6\u3002<\/p>\n\n\n\n

\u201ci\u201d\u4fee\u9970\u7b26\u6807\u8bb0\u7528\u4e8e\u5b9a\u4e49\u6b63\u5219\u8868\u8fbe\u5f0f\u5bf9\u8c61\u6267\u884c\u5927\u5c0f\u5199\u4e0d\u654f\u611f\u7684\u68c0\u7d22
var strtxt=\"Hello EcmaScript!\";
reg1=\/E\/i;
abc=reg1.exec(strtxt);<\/code>
\u5219abc\u5f97\u5230\u8fd4\u56de\u503c\u662f\u201ce\u201d\u3002<\/p>\n\n\n\n

“g”\u548c”i”\u8fd8\u53ef\u7ec4\u5408\u8d77\u6765\u4e00\u8d77\u4f7f\u7528\u3002<\/p>\n\n\n\n

RegExp\u5bf9\u8c61\u5c5e\u6027<\/p>\n\n\n\n

1\u3001global\u5c5e\u6027
\u7528\u4e8e\u8fd4\u56de\u6b63\u5219\u8868\u8fbe\u5f0f\u662f\u5426\u5b9a\u4e49\u4e86”g”\u4fee\u9970\u7b26\u6807\u8bb0\uff0c\u5b9a\u4e49\u4e86\u5219\u8fd4\u56detrue\uff0c\u53cd\u4e4b\uff0c\u8fd4\u56defalse
2\u3001ignoreCase\u5c5e\u6027
\u7528\u4e8e\u8fd4\u56de\u6b63\u5219\u8868\u8fbe\u5f0f\u662f\u5426\u5b9a\u4e49\u4e86”i”\u4fee\u9970\u7b26\u6807\u8bb0\uff0c\u5b9a\u4e49\u4e86\u5219\u8fd4\u56detrue\uff0c\u53cd\u4e4b\uff0c\u8fd4\u56defalse
3\u3001lastIndex\u5c5e\u6027
\u7528\u4e8e\u89c4\u5b9a\u4e0b\u6b21\u68c0\u7d22\u5339\u914d\u7684\u8d77\u59cb\u4f4d\u7f6e\uff0c\u5c5e\u6027\u9ed8\u8ba4\u503c\u4e3a0\uff0c\u8868\u793a\u4ece\u7b2c\u4e00\u4e2a\u5b57\u7b26\u5f00\u59cb\u68c0\u7d22\uff0c\u5f53\u68c0\u7d22\u5230\u6700\u540e\u4e00\u4e2a\u5b57\u7b26\u540e\uff0c\u5176\u503c\u4e3a\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002
4\u3001source\u5c5e\u6027
\u8fd4\u56de\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u6e90\u6587\u672c\uff08\u4e0d\u5e26\u4fee\u9970\u7b26\u6807\u8bb0\uff09<\/p>\n\n\n\n

RegExp\u5bf9\u8c61\u6a21\u5f0f<\/p>\n\n\n\n

1\u3001\u65b9\u62ec\u53f7<\/strong>
[abc]\u8868\u793a\u5339\u914d\u5230abc\u5176\u4e2d\u4e00\u4e2a\u5b57\u7b26\u5373\u53ef
[^abc]\u8868\u793a\u5339\u914d\u5230\u4efb\u610f\u975eabc\u5176\u4e2d\u4e00\u4e2a\u5b57\u7b26\u5373\u53ef
[A-z]\u8868\u793a\u5339\u914d\u5230\u4efb\u610f\u82f1\u6587\u5b57\u6bcd\u5373\u53ef\uff08\u4e0d\u533a\u5206\u5927\u5c0f\u5199\uff09
[^A-z]\u8868\u793a\u5339\u914d\u5230\u4efb\u610f\u975e\u82f1\u6587\u5b57\u6bcd\u5373\u53ef
[0-9]\u8868\u793a\u5339\u914d\u5230\u6570\u5b57\u5373\u53ef
[78]\u8868\u793a\u5339\u914d\u5230\u6570\u5b577\u62168\u5176\u4e2d\u4e00\u4e2a\u5373\u53ef
\u4f8b\uff1a
var strtxt=\"Hello EcmaScript!\";
var reg1=\/[abc]\/;
var result1=reg1.test(strtxt);<\/code>
\u5219result1\u5f97\u5230\u8fd4\u56de\u503ctrue
\u518d\u4f8b\uff1a
var strtxt=\"HelloEcmaScript\";
var reg2=\/[^A-z]\/;
var result2=reg2.test(strtxt);<\/code>
\u5219result2\u5f97\u5230\u8fd4\u56de\u503cfalse<\/p>\n\n\n\n

2\u3001\u5143\u5b57\u7b26<\/strong>
\\w,\\d,\\s,\\b,.,\\xdd
\\w\u53ef\u68c0\u7d22\u5b57\u7b26\u548c\u6570\u5b57\uff0c\u4e0d\u80fd\u68c0\u7d22\u7a7a\u683c\uff0c\u6807\u70b9\u7b26\u53f7\u7b49\u5176\u4ed6\u5b57\u7b26\u5219\u8fd4\u56denull<\/strong>
\u4f8b\uff1a
var strtxt =\"Hi 123!\";
var reg1=\/\\w\/g;
var result;
for (var i=0;i<6;i++)
{
\u00a0\u00a0\u00a0\u00a0result=reg1.exec(strtxt);
\u00a0\u00a0\u00a0\u00a0console.log(result);
}<\/code>
\u53ef\u4f9d\u6b21\u8f93\u51fa”H”,”i”,”1″,”2″,”3″,null
\\d\u53ef\u4ee5\u68c0\u7d22\u6570\u5b57\uff0c\u4f46\u4e0d\u80fd\u68c0\u7d22\u5b57\u6bcd\u5b57\u7b26\uff0c\u5982\u679c\u662f\u6807\u70b9\u7b26\u53f7\u7b49\u5176\u4ed6\u5b57\u7b26\u5219\u8fd4\u56denull<\/strong>
\u4f8b\uff1a
var strtxt =\"Hi 123!\";
var reg1=\/\\d\/g;
var result;
for (var i=0;i<4;i++)
{
\u00a0\u00a0\u00a0\u00a0result=reg1.exec(strtxt);
\u00a0\u00a0\u00a0\u00a0console.log(result);
} <\/code>
\u53ef\u4f9d\u6b21\u8f93\u51fa “1”,”2″,”3″,null
\\s\u53ef\u4ee5\u68c0\u7d22\u7a7a\u767d\u5b57\u7b26\uff08\u5373\u7a7a\u683c\uff09,\u5982\u679c\u662f\u6807\u70b9\u7b26\u53f7\u5219\u8fd4\u56denull<\/strong>
\u4f8b\uff1a
var strtxt =\"Hi 123!\";
var reg1=\/\\s\/g;
var result;
for (var i=0;i<3;i++)
{
\u00a0\u00a0\u00a0\u00a0result=reg1.exec(strtxt);
\u00a0\u00a0\u00a0\u00a0console.log(result);
} <\/code>
\u4f9d\u6b21\u8f93\u51fa” “,null,” “
\\b\u53ef\u68c0\u7d22\u5355\u8bcd\uff08\u6709\u7a7a\u683c\u9694\u5f00\u624d\u7b97\u4e00\u4e2a\u5b8c\u6574\u5355\u8bcd\uff09<\/strong>
\u4f8b\uff1a
var strtxt =\"Hi 123!\";
var strtxt2 =\"Hi123\";
var reg1=\/Hi\\b\/g;
var result = reg1.exec(strtxt);
var result2 = reg1.exec(strtxt2);<\/code>
result\u80fd\u5f97\u5230\u8fd4\u56de\u503cHi\uff0cresult2\u53ea\u6709null
.\u53ef\u4ee3\u6307\u4efb\u610f\u5355\u4e2a\u5b57\u7b26<\/strong>
\u4f8b\uff1a
var strtxt=\"Elmo also loops!\";
var reg1=\/l.o\/g;
var result;
for (var i=0;i<3;i++)
{
\u00a0\u00a0\u00a0\u00a0result=reg1.exec(strtxt);
\u00a0\u00a0\u00a0\u00a0console.log(result);
} <\/code>
\u4f9d\u6b64\u80fd\u8f93\u51falmo\uff0clso\uff0cloo
\\xdd\u53ef\u4ee3\u8868\u963f\u65af\u514b\u7801\u8868\u4e0a\u7684\u5b57\u7b26\uff0c\u4f8b\\x41\u4e3a”A”\uff0c\\x61\u4e3a”a”\uff0c\\x38\u4e3a”8″<\/strong><\/p>\n\n\n\n

3\u3001\u91cf\u8bcd
*\uff0c+\uff0c?\uff0c{x}\uff0c{x,y}\uff0c{x,}
*\u7528\u4e8e\u5339\u914d0\u6b21\u81f3\u591a\u6b21\u91cd\u590d\u7684\u5b57\u7b26
+\u7528\u4e8e\u5339\u914d1\u6b21\u81f3\u591a\u6b21\u91cd\u590d\u7684\u5b57\u7b26
?\u7528\u4e8e\u5339\u914d0\u6b21\u62161\u6b21\u91cd\u590d\u7684\u5b57\u7b26<\/strong>
\u4f8b\uff1a
var strtxt=\"H Hi Hii Hiii\";
var reg1=\/Hi*\/g;
var result1;
for (var i =0;i <=3;i++)
{
\u00a0\u00a0\u00a0\u00a0result1=reg1.exec(strtxt);
\u00a0\u00a0\u00a0\u00a0console.log(result1);
}<\/code>
\u5219\u4f1a\u4f9d\u6b21\u8f93\u51fa”H”,”Hi”,”Hii”,”Hiii”
\u5c06*\u6539\u6210+\uff0c\u5219\u4f1a\u8f93\u51fa “Hi”,”Hii”,”Hiii”
\u5c06*\u6539\u6210?,\u5219\u4f1a\u8f93\u51fa “H”,”Hi”
{x}\uff0c{x,y}\uff0c{x,} \u7528\u4e8e\u5339\u914d\u5b57\u7b26\u6216\u6570\u5b57\u91cd\u590d\u51fa\u73b0\u7684\u56fa\u5b9a\u6b21\u6570<\/strong>
\u4f8b\uff1a
var strnum= \"8 88 888 8888 88888\";
var reg1=\/8{1}\/g;
var result2;
for (var i =0;i <=5;i++)
{
\u00a0\u00a0\u00a0\u00a0result2=reg1.exec(strnum);
\u00a0\u00a0\u00a0\u00a0console.log(result2);
} <\/code>
\u5219\u4f1a\u4f9d\u6b21\u8f93\u51fa”8″,”8″,”8″,”8″,”8″
\u82e5\u5c06{1}\u6539\u4e3a{3}\uff0ci<=5\u6539\u4e3ai<=3,\u5219\u4f1a\u4f9d\u6b21\u8f93\u51fa”888″,”888″,”888″
\u82e5\u5c06{1}\u6539\u4e3a{2,4}\uff0ci<=5\u6539\u4e3ai<=3 \uff0c\u5219\u4f1a\u4f9d\u6b21\u8f93\u51fa”88″,”888″,”8888″
\u82e5\u5c06{1}\u6539\u4e3a{2,}\uff0ci<=5\u6539\u4e3ai<=4\uff0c\u5219\u4f1a\u4f9d\u6b21\u8f93\u51fa”88″,”888″,”8888″,”88888″
^\u548c$\u8fd8\u53ef\u5339\u914d\u6574\u4e2a\u5b57\u7b26\u4e32\u7684\u5f00\u5934\u548c\u7ed3\u5c3e<\/strong>
var strtxt=\"Hi Hii Hiii\";
var reg3=\/^Hi\/g;
result3=reg3.exec(strtxt);<\/code>
\u5219result3\u53ef\u5f97\u5230\u8fd4\u56de\u503cHi, \u6362\u6210\/^Hii\/g\u5219\u53ea\u4f1a\u8fd4\u56denull
(\u7528$\u65f6\u653e\u5728\u540e\u9762\uff0c\u5982var reg4=\/Hiii$\/g<\/code>)

var reg4=\/\\d{4}-\\d{2}-\\d{2}|\\d{8}\/;<\/code>\u53ef\u67e5\u627e\u683c\u5f0f\u4e3a2019-04-06\u6216\u800520190406\u7684\u65e5\u671f<\/p>\n","protected":false},"excerpt":{"rendered":"

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