为什么`pattern.test（name）`在连续调用时产生相反的结果 [英] Why `pattern.test(name)` opposite results on consecutive calls

问题描述

为什么此代码首先返回true，然后返回false

Why is this code returning first true, then false

var pattern = new RegExp("mstea", 'gi'), name = "Amanda Olmstead";

console.log('1', pattern.test(name));
console.log('1', pattern.test(name));

演示：小提琴

推荐答案

g 用于重复搜索。它将正则表达式对象更改为迭代器。如果你想使用 test 函数来检查你的字符串是否有效，请删除这个修饰符：

g is for repeating searches. It changes the regular expression object into an iterator. If you want to use the test function to check your string is valid according to your pattern, remove this modifier :

var pattern = new RegExp("mstea", 'i'), name = "Amanda Olmstead";

测试函数，与<$相反c $ c> replace 或 match 不会消耗整个迭代，这使得它处于坏状态。使用 test 函数时，您可能永远不会使用此修饰符。

The test function, contrary to replace or match doesn't consume the whole iteration, which lets it in a "bad" state. You should probably never use this modifier when using the test function.

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