function splice(arr,target) {
    let n=0
    let len = arr.length
    for(let i=0;i<len;i++) {
        if(arr[i]!== target) { 
            arr[n++]=arr[i] 
        }       
    } 
    arr.length-= len-n     
    return arr
}
console.log(splice([3,2,3,3,5,4],3))