onSelectionChanged(event) {
    let selectdata = event['api']['immutableService']['gridOptionsWrapper']['gridOptions']['rowData'];
    let selected_flag = 0;

    selectdata.forEach(data => {
      if (data.selected == true) {
        selected_flag = 1;
      }
    });

    if (selected_flag == 1) {
      this.showForms = true;
    } else {
      this.showForms = false;
    }
}

请使用ForEach的一些或所有实例，

Array.prototype.some:
some is much the same as forEach but it break when the callback returns true

Array.prototype.every:
every is almost identical to some except it's expecting false to break the loop.

例如:

var ary = ["JavaScript", "Java", "CoffeeScript", "TypeScript"];

ary.some(function (value, index, _ary) {
    console.log(index + ": " + value);
    return value === "JavaScript";
});

每个的例子:

var ary = ["JavaScript", "Java", "CoffeeScript", "TypeScript"];

ary.every(function(value, index, _ary) {
    console.log(index + ": " + value);
    return value.indexOf("Script") > -1;
});

查找更多信息 http://www.jsnoob.com/2013/11/26/how-to-break-the-foreach/

正如其他答案所说，Angular不提供这个功能。而jQuery可以，如果你已经加载了jQuery和Angular，你就可以使用它

jQuery.each ( array, function ( index, value) {
    if(condition) return false; // this will cause a break in the iteration
})

参见http://api.jquery.com/jquery.each/

我更喜欢用return来做。将循环部分放在私有函数中，并在想要打破循环时返回。

这个例子有用。试一试。

var array = [0,1,2];
for( var i = 0, ii = array.length; i < ii; i++){
  if(i === 1){
   break;
  }
}

只需添加$index并执行以下操作:

angular.forEach([0,1,2], function(count, $index) {
     if($index !== 1) {
          // do stuff
     }
}