前端算法-leecode-20 有效的括号

/**
 * @param {string} s
 * @return {boolean}
 */
var isValid = function(s) {
const mapping = new Map()
mapping.set('(',')');
mapping.set('{','}');
mapping.set('[',']');
const stack = [];
for(let i=0;i<s.length;i++){
    if(mapping.has(s[i])){
        stack.push(mapping.get(s[i]))
    }else{
        if(stack.pop(s[i]) !== s[i]){
            return false
        }
    }

}
if(stack.length>0){
    return false
}
return true
};