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<script>
//查照'hsadhasadsdhahshdhsajjsa'里面h的位置以及个数
var str = 'hsadhasadsdhahshdhsajjsa';
var index = str.indexOf('h');
var num = 0; //获取个数
while (index !== -1) {
console.log(index); //输出位置 先把第一个索引号输出
num++;
index = str.indexOf('h', index + 1) //给她后面加一个输出的索引号+1 要从这个索引号开始查询
}
console.log('h的个数有' + num + '个');
</script>
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