Finds the first index of a given element in an array using the linear search algorithm.
- Use a
for...in
loop to iterate over the indexes of the given array. - Check if the element in the corresponding index is equal to
item
. - If the element is found, return the index, using the unary
+
operator to convert it from a string to a number. - If the element is not found after iterating over the whole array, return
-1
.
代码实现
const linearSearch = (arr, item) => {
for (const i in arr) {
if (arr[i] === item) return +i;
}
return -1;
};
linearSearch([2, 9, 9], 9); // 1
linearSearch([2, 9, 9], 7); // -1