getAryFirIndex(arr, text) {// 若元素不存在在数组中返回-1let firstVal = -1for (let i = 0; i < arr.length; i++) {// json (arr[i].id == text)if (arr[i] === text) {firstVal = ireturn firstValbreak}}return firstVal}let ary = ['1','2','4','1','2']
getAryFirIndex(ary , '1')
备注：如果是JSON对象的数据 将arr[i]改为arr[i].对象名