查找子字符串时无法返回数组长度

Question

当满足子字符串条件时，如何返回数组的长度？我有三个数组：

arr1 = ["V1","V1","V1","V1","V1","V2","V2","V2"...]
arr2 = ["A1","A1","B1","B1","B1","A2","A2","A2"...]
arr3 = ["V1A1*","V1A1*","V1B1*","V1B1*"...]

Answer 1

看起来您是说这三个数组的长度相同，对于数组的每个索引i，您想知道ARR1[i]+ARR2[i]是否是ARR3[i]的子字符串。然后，你想知道有多少元素符合这个标准。

为此，您需要查看数组的索引，并使用String.indexOf方法查看是否满足条件。

var length = arr1.length,
    matchCount = 0,
    isMatch, i;

for(i = 0; i < length; i += 1) {
    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/indexOf
    // indexOf returns the array index where the substring is found, or -1 if it is not found
    isMatch = arr3[i].indexOf(arr1[i] + arr2[i]) > -1;
    if (isMatch) {
        matchCount += 1;
    }
}

console.log(matchCount);