2) Using indexOf() to count occurrences of a substring in a string · First, use the indexOf() method to find the first occurrence of the substr in the str . ... <看更多>

Instances of the String constructor have a .search() method which accepts a RegExp and returns the index of the first match. To start the search from a ... ... <看更多>

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findIndex(el => el == str) return result; } let strData = '123456' let arrData = [1,2,3]; console.log(_indexOf(1,strData),'strData'); ... ... <看更多>