如何检查一个字符串是否包含子字符串在 JavaScript 中？

Question

Usually I would expect a String.contains() method, but there doesn't seem to be one.

What is a reasonable way to check for this?

转载于:https://stackoverflow.com/questions/1789945/how-to-check-whether-a-string-contains-a-substring-in-javascript

Answer 1

Here is a list of current possibilities:

1. (ES6) includes—go to answer

var string = "foo",
    substring = "oo";
string.includes(substring);

2. ES5 and older indexOf

var string = "foo",
    substring = "oo";
string.indexOf(substring) !== -1;

String.prototype.indexOf returns the position of the string in the other string. If not found, it will return -1.

3. search—go to answer

var string = "foo",
    expr = /oo/;
string.search(expr);

4. lodash includes—go to answer

var string = "foo",
    substring = "oo";
_.includes(string, substring);

5. RegExp—go to answer

var string = "foo",
    expr = /oo/;  // no quotes here
expr.test(string);

6. Match—go to answer

var string = "foo",
    expr = /oo/;
string.match(expr);

---

Performance tests are showing that indexOf might be the best choice, if it comes to a point where speed matters.