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]);
}
}());