How does js determine whether a string contains a character?

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1. Use the string search () method

The search () method is used to retrieve a substring specified in a string or to retrieve a substring that matches a regular expression. If no matching substring is found,-1 is returned.

Var string = "foo", expr = / oo/;string.search (expr); / / location is 1

2. Use the string match () method

The match () method retrieves the specified value within a string or finds a match of one or more regular expressions.

Var string = "foo", expr = / oo/;string.match (expr); / / ["oo", index: 1, input: "foo", groups: undefined]

3. Use the regular test () method

The test () method is used to retrieve the value specified in the string. Returns true or false.

Let str= "abc" let reg=RegExp (/ b /) console.log (reg.test (str)) / / true

4. Use the regular exec () method

The exec () method is used to retrieve the match of a regular expression in a string. Returns an array containing the matching results. If no match is found, the return value is null.

Var groupName= "Xiaobai Group A"; var reg = RegExp (/ group /); alert ('reg.exec (groupName) =' + (reg.exec (groupName) / / Group Thank you for your reading. The above is the content of "how js determines whether a string contains a character". After the study of this article, I believe you have a deeper understanding of how js determines whether a string contains a character, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!