如何在同一行中解释=和===？ [英] How to interpret = and === in the same line?

问题描述

我遇到过这段代码

render: function() {
    var boards = [];
    for (var ii = 0; ii < this.props.numBoards; ii++) {
      // We can compare to state here so we're no longer always selecting the first board.
      var isSelected = ii === this.state.selectedIndex;
      boards.push(
        <Board index={ii} selected={isSelected}  />

      );
    }

行如何选择= ii === this.state.selectedIndex 执行了吗？

以下是完整代码： http://jsbin.com/dagavu/4/embed?css,js,output

推荐答案

以下代码分两步执行

isSelected = ii === this.state.selectedIndex

1. ii === this.state.selectedIndex // comparator operator
2. isSelected = (result of step 1) // assignment operator

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