String.prototype.search()

search() 方法执行正则表达式和 String 对象之间的一个搜索匹配。

语法

str.search(regexp)

参数

regexp
一个正则表达式(regular expression)对象。如果传入一个非正则表达式对象 obj,则会使用 new RegExp(obj) 隐式地将其转换为正则表达式对象。

返回值

如果匹配成功,则 search() 返回正则表达式在字符串中首次匹配项的索引;否则,返回 -1

描述

当你想要知道字符串中是否存在某个模式(pattern)时可使用 search(),类似于正则表达式的 test() 方法。当要了解更多匹配信息时,可使用 match()(但会更慢一些),该方法类似于正则表达式的 exec() 方法。

示例

例子:使用 search()

下面的例子中用两个不同的正则表达式对同一个字符串执行搜索匹配,得到一个成功匹配(正数返回值)和一个失败匹配(-1)。

var str = "hey JudE";
var re = /[A-Z]/g;
var re2 = /[.]/g;
console.log(str.search(re)); // returns 4, which is the index of the first capital letter "J"
console.log(str.search(re2)); // returns -1 cannot find '.' dot punctuation

规范

规范 状态 备注
ECMAScript 3rd Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.2.
ECMAScript 5.1 (ECMA-262)
String.prototype.search
Standard
ECMAScript 2015 (6th Edition, ECMA-262)
String.prototype.search
Standard
ECMAScript Latest Draft (ECMA-262)
String.prototype.search
Draft

浏览器兼容性

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
searchChrome Full support YesEdge Full support 12Firefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes
flags
DeprecatedNon-standard
Chrome No support NoEdge No support NoFirefox No support 1 — 49IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoFirefox Android No support 4 — 49Opera Android No support NoSafari iOS No support NoSamsung Internet Android No support Nonodejs No support No

Legend

Full support  
Full support
No support  
No support
Non-standard. Expect poor cross-browser support.
Non-standard. Expect poor cross-browser support.
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.

Gecko 注意事项

  • Gecko 8.0 及之前的版本,search() 的实现有问题:在调用该方法时,若不传递参数或者参数为 undefined,该方法将不会匹配空字符串,而是匹配字符串 "undefined"。这个问题已被修复,现在,"a".search() 和 "a".search(undefined) 都能正确返回 0。
  • Starting with Gecko 39 (Firefox 39 / Thunderbird 39 / SeaMonkey 2.36), the non-standard flags argument is deprecated and throws a console warning (bug 1142351).
  • Starting with Gecko 47 (Firefox 47 / Thunderbird 47 / SeaMonkey 2.44), the non-standard flags argument is no longer supported in non-release builds and will soon be removed entirely (bug 1245801).
  • Starting with Gecko 49 (Firefox 49 / Thunderbird 49 / SeaMonkey 2.46), the non-standard flags argument is no longer supported (bug 1108382).

参见