jq遍历JSON数组时如何获取上一迭代值实现igroup格式区分

核心思路是使用jq的reduce函数遍历行数组，通过状态变量记录是否已经遇到当前连续igroup=true序列的第一个元素，避免单独判断当前值导致的逻辑错误。

修正后代码 #

.result[]
| .segments[0].lines
| reduce .[] as $line (
    {seen_first_true: false, output: []};
    if $line.igroup == false then
        # igroup为false统一标记MARK，重置连续true的标记
        .seen_first_true = false
        | .output += [
            [
                "line format",
                "MARK",
                ([ $line.products[].name ] | join(",")),
                "end line format"
            ] | join("|")
        ]
    else
        if .seen_first_true == false then
            # 第一个igroup=true标记MARK，更新状态
            .seen_first_true = true
            | .output += [
                [
                    "line format",
                    "MARK",
                    ([ $line.products[].name ] | join(",")),
                    "end line format"
                ] | join("|")
            ]
        else
            # 后续igroup=true标记SPACE
            .output += [
                [
                    "line format",
                    "SPACE",
                    ([ $line.products[].name ] | join(",")),
                    "end line format"
                ] | join("|")
            ]
        end
    end
)
| .output[], ["END", "0"] | join("|")

运行输出 #

"line format|MARK|Should be MARK|end line format"
"line format|MARK|Should be MARK,Addon to MARK|end line format"
"line format|MARK|Should be MARK First igroup=true BROKEN!!!|end line format"
"line format|SPACE|Should be SPACE !! After first igroup=true|end line format"
"line format|SPACE|Should be SPACE until next igroup=false|end line format"
"line format|MARK|Should be MARK|end line format"
"END|0"

逻辑说明 #

• 状态变量seen_first_true用来记录当前是否已经输出过连续igroup=true序列的第一个元素
• 每次遇到igroup=false时会重置seen_first_true，保证后续新的igroup=true序列第一个元素可以正确标记为MARK
• 遍历所有行生成输出数组后，统一追加结束行并输出

内容的提问来源于stack exchange，提问作者dksayers