错误提示
Warning: String.charAt is deprecated; use String.prototype.charAt instead Warning: String.charCodeAt is deprecated; use String.prototype.charCodeAt instead Warning: String.concat is deprecated; use String.prototype.concat instead Warning: String.contains is deprecated; use String.prototype.contains instead Warning: String.endsWith is deprecated; use String.prototype.endsWith instead Warning: String.includes is deprecated; use String.prototype.includes instead Warning: String.indexOf is deprecated; use String.prototype.indexOf instead Warning: String.lastIndexOf is deprecated; use String.prototype.lastIndexOf instead Warning: String.localeCompare is deprecated; use String.prototype.localeCompare instead Warning: String.match is deprecated; use String.prototype.match instead Warning: String.normalize is deprecated; use String.prototype.normalize instead Warning: String.replace is deprecated; use String.prototype.replace instead Warning: String.search is deprecated; use String.prototype.search instead Warning: String.slice is deprecated; use String.prototype.slice instead Warning: String.split is deprecated; use String.prototype.split instead Warning: String.startsWith is deprecated; use String.prototype.startsWith instead Warning: String.substr is deprecated; use String.prototype.substr instead Warning: String.substring is deprecated; use String.prototype.substring instead Warning: String.toLocaleLowerCase is deprecated; use String.prototype.toLocaleLowerCase instead Warning: String.toLocaleUpperCase is deprecated; use String.prototype.toLocaleUpperCase instead Warning: String.toLowerCase is deprecated; use String.prototype.toLowerCase instead Warning: String.toUpperCase is deprecated; use String.prototype.toUpperCase instead Warning: String.trim is deprecated; use String.prototype.trim instead Warning: String.trimLeft is deprecated; use String.prototype.trimLeft instead Warning: String.trimRight is deprecated; use String.prototype.trimRight instead
错误类型
警告。JavaScript 引擎不会停止运行。
哪里出错了?
非标准的泛型 String
方法已经被废弃,将来会被移除(这些方法仅在 Firefox 浏览器中得到实现)。String 泛型在 String 对象上提供了一系列的 String 实例方法,使得这些 String 方法可以应用于任何类型的对象。
Firefox bug 1222552 对 String 泛型方法的移除进行了追踪。
示例
废弃的语法
var num = 15; String.replace(num, /5/, '2');
标准语法
var num = 15; String(num).replace(/5/, '2');
垫片
以下是一个垫片脚本来为不支持 String 泛型方法浏览器提供支持:
/*globals define*/ // Assumes all supplied String instance methods already present // (one may use shims for these if not available) (function() { 'use strict'; var i, // We could also build the array of methods with the following, but the // getOwnPropertyNames() method is non-shimable: // Object.getOwnPropertyNames(String).filter(function(methodName) { // return typeof String[methodName] === 'function'; // }); methods = [ 'contains', 'substring', 'toLowerCase', 'toUpperCase', 'charAt', 'charCodeAt', 'indexOf', 'lastIndexOf', 'startsWith', 'endsWith', 'trim', 'trimLeft', 'trimRight', 'toLocaleLowerCase', 'normalize', 'toLocaleUpperCase', 'localeCompare', 'match', 'search', 'slice', 'replace', 'split', 'substr', 'concat', 'localeCompare' ], methodCount = methods.length, assignStringGeneric = function(methodName) { var method = String.prototype[methodName]; String[methodName] = function(arg1) { return method.apply(arg1, Array.prototype.slice.call(arguments, 1)); }; }; for (i = 0; i < methodCount; i++) { assignStringGeneric(methods[i]); } }());