let arr = ['1','2','3'];
let a = '1';
arr.forEach(function((item, index, arr) {
if (item === a) {
arr.splice(index, 1);
}
});
let arr = ['1','2','3'];
let a = '1';
arr.forEach(function((item, index, arr) {
if (item === a) {
arr.splice(index, 1);
}
});