Splice（）函数未按预期工作

Question

I'm trying to remove a particular element from an array in JavaScript using splice() function but I'm not able to delete the target element.

    var a = [];
    a.push("cs");
    a.push("ac");
    var curr2 = a.indexOf("ac");
    if(curr2 != -1){
        a = a.splice(curr2,1);
    } 
    console.log(a);

Expected result : ["cs"] Actual Result : ["ac"]

Can someone explain this behaviour. Thanks!

Answer 1

That's because Splice return the elements that you removed.

Remember that Splice modifies the original Array so when you make

a = a.splice(curr2,1);

You are storing the elements removed.

Replace that line with

a.splice(curr2,1);

And that should solve your problem!

Answer 2

You code is pulling 1 element from the array starting at index 1:

 var a = []; a.push("cs"); a.push("ac"); var curr2 = a.indexOf("ac"); console.log("curr2 = " + curr2); // curr2 = 1; if (curr2 != -1) { var b = a.slice(); b.splice(curr2, 1); console.log(b); // ["ac"] var c = a.slice(); c.splice(1, 1); console.log(c); // ["ac"] } 

Answer 3

splice returns the item you have deleted in a array. In short, change a = a.splice(curr2,1); to a.splice(curr2,1); and your code will work as expected. Since splice modifies the array you will get an array without the desired element. Where as before you were reassigning a to the return value of splice