{"id":77,"date":"2011-12-24T17:51:30","date_gmt":"2011-12-24T09:51:30","guid":{"rendered":"https:\/\/blog.indeex.club\/?p=77"},"modified":"2020-06-20T22:44:04","modified_gmt":"2020-06-20T14:44:04","slug":"javascript-%e7%bb%9f%e8%ae%a1%e5%ad%97%e7%ac%a6%e5%87%ba%e7%8e%b0%e9%a2%91%e7%8e%87","status":"publish","type":"post","link":"https:\/\/blog.indeex.club\/index.php\/2011\/12\/24\/javascript-%e7%bb%9f%e8%ae%a1%e5%ad%97%e7%ac%a6%e5%87%ba%e7%8e%b0%e9%a2%91%e7%8e%87\/","title":{"rendered":"Javascript \u7edf\u8ba1\u5b57\u7b26\u51fa\u73b0\u9891\u7387"},"content":{"rendered":"<pre><code class=\"line-numbers\">&lt;script type=\"text\/javascript\"&gt;\n    var str = \"adadfdfseffserfefsefseeffffftsdg\"; \/\/\u547d\u540d\u4e00\u4e2a\u53d8\u91cf\u653e\u7f6e\u7ed9\u51fa\u7684\u5b57\u7b26\u4e32  \n    var maxLength = 0; \/\/\u547d\u540d\u4e00\u4e2a\u53d8\u91cf\u653e\u7f6e\u5b57\u6bcd\u51fa\u73b0\u7684\u6700\u9ad8\u6b21\u6570\u5e76\u521d\u59cb\u5316\u4e3a0  \n    var result = ''; \/\/\u547d\u540d\u4e00\u4e2a\u53d8\u91cf\u653e\u7f6e\u7ed3\u679c\u8f93\u5165   \n    while(str != '') { \/\/\u5faa\u73af\u8fed\u4ee3\u5f00\u59cb\uff0c\u5e76\u5224\u65ad\u5b57\u7b26\u4e32\u662f\u5426\u4e3a\u7a7a   \n        oldStr = str; \/\/\u5c06\u539f\u59cb\u7684\u5b57\u7b26\u4e32\u53d8\u91cf\u8d4b\u503c\u7ed9\u65b0\u53d8\u91cf   \n        getStr = str.substr(0, 1); \/\/\u7528\u5b57\u7b26\u4e32\u7684substr\u7684\u65b9\u6cd5\u5f97\u5230\u7b2c\u4e00\u4e2a\u5b57\u7b26\uff08\u9996\u5b57\u6bcd\uff09   \n        eval(\"str = str.replace(\/\" + getStr + \"\/g,'')\"); \/\/\u8be6\u7ec6\u5982\u8865\u5145    \n        if(oldStr.length - str.length &gt; maxLength) { \/\/\u5224\u65ad\u539f\u59cb\u7684\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u51cf\u53bb\u66ff\u4ee3\u540e\u5b57\u7b26\u4e32\u957f\u5ea6\u662f\u5426\u5927\u4e8e\u4e4b\u524d\u51fa\u73b0\u7684\u6700\u5927\u7684\u5b57\u7b26\u4e32\u957f\u5ea6   \n            maxLength = oldStr.length - str.length; \/\/\u4e24\u5b57\u7b26\u4e32\u957f\u5ea6\u76f8\u51cf\u5f97\u5230\u6700\u5927\u7684\u5b57\u7b26\u4e32\u957f\u5ea6\n            result = getStr + \"=\" + maxLength \/\/\u8fd4\u56de\u6700\u5927\u7684\u5b57\u7b26\u4e32\u7ed3\u679c\uff08\u5b57\u6bcd\u3001\u51fa\u73b0\u6b21\u6570\uff09   }  }  \n            alert(result) \/\/\u5f39\u51fa\u7ed3\u679c\n&lt;\/script&gt;\n<\/code><\/pre>\n<p>\u8865\u5145\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">eval(\"str = str.replace(\/\"+getStr+\"\/g,'')\");\n<\/code><\/pre>\n<p>\u53ef\u80fd\u5f88\u591a\u4eba\u60f3\u8fd9\u6837\u5199 str = str.replace(\/getStr\/g,\u201d)\uff0c\u53ef\u7ed3\u679c\u5374\u662f\u4f1a\u51fa\u9519\u7684\u3002\u4e3a\u4ec0\u4e48\u5462\uff0c\u5728\u8fd9\u53e5\u4e2d\u6b63\u5219\u8868\u8fbe\u5f0f\u5339\u914d\u7684\u662f getStr \u5b57\u7b26\u4e32\uff0c\u800c\u4e0d\u662f getStr \u6307\u5411\u7684\u9996\u5b57\u6bcd\u3002\u901a\u8fc7 eval \u65b9\u6cd5\u53ef\u4ee5\u907f\u514d\uff08\u9996\u5148 getStr \u5f97\u5230\u6307\u5411\u7684\u9996\u5b57\u6bcd\uff0c\u7528\u5b57\u7b26\u4e32\u8fde\u63a5 \u201cstr = str.replace(\/\u201d+getStr+\u201d\/g,\u201d)\u201d\uff0c\u6700\u540e\u5728 eval \u4e2d\u6267\u884c\u8fd9\u6bb5\u4ee3\u7801\uff0c\u5373\uff1a\u5148\u89e3\u91caJavascript \u4ee3\u7801\uff0c\u7136\u540e\u518d\u6267\u884c\u5b83\uff09\u3002<\/p>\n<p>\u7531\u4e8e eval \u6027\u80fd\u4e0d\u597d\uff0c\u5bb9\u6613\u51fa\u9519\uff0c\u800c\u4e14\u53ef\u8bfb\u6027\u4e0d\u597d\u3002\u5efa\u8bae\u5c06 eval(\u201dstr = str.replace(\/\u201d+getStr+\u201d\/g,\u201d)\u201d) \u6539\u4e3a\uff1a<\/p>\n<p>str = str.replace(new RegExp(getStr,&#8221;g&#8221;),&#8221;&#8221;)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&lt;script type=&#8221;text\/javascript&#8221;&gt; var str = &#8220;a<a href=\"https:\/\/blog.indeex.club\/index.php\/2011\/12\/24\/javascript-%e7%bb%9f%e8%ae%a1%e5%ad%97%e7%ac%a6%e5%87%ba%e7%8e%b0%e9%a2%91%e7%8e%87\/\" class=\"read-more\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[4],"_links":{"self":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/77"}],"collection":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/comments?post=77"}],"version-history":[{"count":1,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/77\/revisions"}],"predecessor-version":[{"id":78,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/77\/revisions\/78"}],"wp:attachment":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/media?parent=77"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/categories?post=77"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/tags?post=77"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}