javascript - 如何退出 Javascript 函数内的循环

Question

我试图在找到值时退出函数调用，但我无法理解这一点。

使用调试器，我注意到 returnfound; 行使执行跳转到函数的末尾，好吧......但之后 for 上的另一次迭代code> 循环开始。

我也尝试过使用break。

我的代码如下。

已编辑

我已经检查了调试器上的逻辑，在 found = true 上添加了一个断点，它工作正常，所以剩下的唯一的事情就是它应该在之后正确退出......

//  Tree traversal until answer found via answer.id

    function locateAnswer(wholeTree, answerID) {
      var found = false;
      if (wholeTree.answers) { // checks if next_queston is populated first

        for (var i = 0; i < wholeTree.answers.length; ++i) {        
          if (wholeTree.answers[i].id == answerID) {

            console.log("found!");
            found = true;
            return found;       // TRIED break; TOO

          } else {
            for (var j = 0; j < $scope.breadcrumbs.length; ++j) {
              if ($scope.breadcrumbs[j].question == wholeTree.question) {
                // if already exist, we pop elements until it does not exist anymore
                while ($scope.breadcrumbs[j]) {
                  $scope.breadcrumbs.pop();
                }
              }
            }

            // we push the new breadcrumb
            $scope.breadcrumbs.push({ "question": wholeTree.question, "answer": wholeTree.answers[i].answer });

            locateAnswer(wholeTree.answers[i].next_question, answerID);
          }
        }
      }
     //  ALSO TRIED return HERE AFTER break
    };

Answer 1

您应该使用break在函数末尾的循环和 return 语句内。请更新代码

function locateAnswer(wholeTree, answerID) {
      var found = false;
      if (wholeTree.answers) { // checks if next_queston is populated first

        for (var i = 0; i < wholeTree.answers.length; ++i) {        
          if (wholeTree.answers[i].id == answerID) {

            console.log("found!");
            var found = true;

          break;        // TRIED break; TOO

          } else {
            for (var j = 0; j < $scope.breadcrumbs.length; ++j) {
              if ($scope.breadcrumbs[j].question == wholeTree.question) {
                // if already exist, we pop elements until it does not exist anymore
                while ($scope.breadcrumbs[j]) {
                  $scope.breadcrumbs.pop();
                }
              }
            }

            // we push the new breadcrumb
            $scope.breadcrumbs.push({ "question": wholeTree.question, "answer": wholeTree.answers[i].answer });

            locateAnswer(wholeTree.answers[i].next_question, answerID);
          }
        }
      }
     //  ALSO TRIED return HERE AFTER break
 return found;
    };