括号匹配-js解答

给定一个字符串，里边可能包含“()”、"{}"、“[]”三种括号，请编写程序检查该字符串的括号是否成对出现。

输出：

true：代表括号成对出现并且嵌套正确，或字符串无括号字符。

false：未正确使用括号字符。

function resolve(str = "(1+2)/(0.5+1)") {
    let arr = str.split("").filter(item => item === "(" || item === ")" || item === "[" || item === "]" || item === "{" || item === "}");
    console.log(arr.join(""));
    let res = [];
    let flag = true;
    for (let i = 0; i < arr.length; i++) {
        if (arr[i] === "(" || arr[i] === "[" || arr[i] === "{") {
            res.push(arr[i])
        }
        if (i === 0 && (arr[i] === ")" || arr[i] === "]" || arr[i] === "}")) {
            flag = false;
            break;
        }
        if (arr[i] === ")" && res[res.length - 1] === "(") {
            res.length = res.length - 1;
        } else if (arr[i] === ")" && res[res.length - 1] !== "(") {
            flag = false;
            break;
        }
        if (arr[i] === "]" && res[res.length - 1] === "[") {
            res.length = res.length - 1;

        } else if (arr[i] === "]" && res[res.length - 1] !== "[") {
            flag = false;
            break;
        }
        if (arr[i] === "}" && res[res.length - 1] === "{") {
            res.length = res.length - 1;

        } else if (arr[i] === "}" && res[res.length - 1] !== "{") {
            flag = false;
            break;
        }
    }
    if (flag && res.length === 0) {
        console.log(true);
    } else {
        console.log(false);
    }
}
resolve();