'in' operator in JavaScript. String comparison

This question already has an answer here:

How to check whether a string contains a substring in JavaScript? 49 answers

---

I think one way is to use String.indexOf()

'aaa' .indexOf('a') > -1

In javascript the in operator is used to check whether an object has a property

---

你正在寻找indexOf 。

'aaa'.indexOf('a') == 0 //if a char exists in the string, indexOf will return
                        // the index of the first instance of the char
'aaa'.indexOf('b') == -1 //if a char doesn't exist in the string, indexOf will return -1

---

Duplicate (How to check whether a string contains a substring in JavaScript?)

Try this:

var s = "aaaabbbaaa";
var result = s.indexOf("a") > -1;

链接地址: http://www.djcxy.com/p/2052.html

上一篇: 检查一个必须包含另一个字符串的字符串

下一篇: 'in'运算符在JavaScript中。 字符串比较